Path Maximum Transmission Unit (PMTU) Black Hole Routers

Windows XP SP3 promises detection of Black Hole Routers, which is supposed to improve over all networking experience especially for laptops. While investigating the subject, I came across a good, comprehensive article about PMTU (Path Maximum Transmission Unit) at Microsoft site.

By default PMTU Black Hole Discovery for TCP/IP is disabled on Windows XP machines. It can be enabled though:

Setting: EnablePMTUBHDetect
Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
Value Type: REG_DWORD Value: 1

"Changes in PMTU black hole router detection in Windows Server 2003 and in Windows Vista" is a good follow up article.

Enabling of PMTU Black Hole detection and changes are all result of Microsoft's "Next Generation TCP/IP Stack".

The Cable Guy from Microsoft has an article on enhancements that "Next Generation TCP/IP Stack" (terrible name IMHO) offers.


Vista BSOD

My vista install started to crash when there is a lot of disk activity. It would crash every other day at first. Then, at some point it started to go down shortly after I initiate PowerUsenet downloads.

I looked at MS documentation for 0x0000007B and concluded that it had something to do with Sata controller. Article suggested to replace cables as it could be caused by a faulty cable but doing so did not help.

Then, I bought a HighPoint Tech TocketRaid 1742 PCI card. Documentation suggested to simply install the card and point to the driver location once Vista detected it. Unfortunately, Vista kept on blue screening once card was installed and I could not reach the logon page.

I installed the card on an empty PCI slot and connected back my Promise SATA controller. After the Vista came up I installed drivers, shutdown pc and removed the promise controller. Then, I reconnected my SATA HDs to the new controller and succesfully booted.

I hope this will end my BSOD issues....Time will show.


Ubuntu 7.10 (Gutsy Gibbon) Test Drive

Ubuntu 7.10 was released yesterday. Below is my first hand impression of new release. The Good, The Bad & The Ugly, if you will...

Getting the image:
I tried all North America mirrors to find a fast image download site but I guess because of first day rush, all were slow, download speeds around 50 KB/s. After a couple of hours, I was able to access Georgia Tech mirror which let me download at speeds of 2MB/s, so I got the image in a matter of mins.

I usually use to order my free copies of Ubuntu, which is an awesome feature of Ubuntu Distro.

Because of firewall rules, I could not use torrents in my environment. Not sure how that would change my experience.

One thing I noticed was that Europe/Asia had a lot more mirrors and when I tried them I got almost the same download speeds: ~50KB/s. I hope more 'fast' mirrors are added for North America soon.

Ubuntu installs were always good but not without hickups... When I was reading reviews, I had read something like 'Installation was even easier than Vista'. I attest to that now.

I decided to wipe out earlier version and install it on my IBM T40. I popped in the CD, live-cd install completed in a few mins. Then I clicked install shortcut on the desktop and installation started.

In all installs up to this version, time would always be incorrect, this worked fine. Install time was short and I had to click 'next' a couple of times to confirm keyboard, regions etc and enter username/pwd.

When I say devices, I should confess that I don't really have a lot of devices to check the functionality. What has always been painful for me was Wireless Access. I have a netgear wireless card, which was automatically recognized, drivers were installed and was ready for me to use after reboot.

The only thing I noticed was, it was not available during install and at some point Ubuntu install warned me that I did not have internet connectivity, so Security Repositories/Updates would not be available at the time. No biggie.

One of the exciting things I saw in 10 rocking features in 10 days series of articles was about Tight integration of Firefox with Ubuntu. So when I browsed to blogger site, firefox popped up a message for "missing plugin".

Unfortunately, things did not work as advertised after that. Flash Plugin was supposed to be installed seemlessly. Instead I got an error when I tried to install it.

In fact, once I clicked "close", it told me that plugin was installed and I needed to restart firefox. Of course, that was not true...

I also tried Firefox > Tool > Addons to install some plugins like GreaseMonkey but no luck there either. It kept on complaining about source not being available. If you look carefully, you will notice a type in "available".

I know some may think I am just being picky now, but I hate to see such typos as it gives you the impression of sloppiness. Ubuntu is a 'high-quality' distro, such small stuff does therefore matter (at least to me).

I am not sure if this is a bug or if there is some back-end issues here though. Because I also got a "Service Outage" page when I was trying to get some more explanation on what's going on.

Anyway, I am sure I can still download and install these stuff manually as I used to.

Screen Resolution: It always bothered me with Ubuntu/linux installs not to be able to easily increase screen resolution from current setting. Ok, "easily" is a relative term. Because normally, you would edit /etc/X11/xorg.conf and then logout / log back in to see changes. That's a "no no".

In fact, in Ubuntu preview, Lifehacker touched upon this point: "It might not seem like a revolutionary feature, but users can now change their screen resolutions and refresh rates without having to log out or hack around in terminal."

I think it should be like in Windows, where all resolutions are listed and when users chooses one, it's tested and user is asked to confirm if it was OK. This is still missing from "easy-to-use" Ubuntu and require a bit more tech skills.

OK, I guess I will post more when I have more time in my hands to play with it. This is it for the time being. Oh, before I forget, I loved the fact that Compiz is the default window manager in Ubuntu now:)

Edit 10/22/2007: I am having an issue with Ubuntu start up. It does not start properly and a black screen is displayed. I play with the mouse and touch a few keys, I see HD activity in the meantime and after a minute or so logon screen shows up. I have an ATI card on this IBM T40 laptop, not sure what exactly is causing this but no update has resolved the issue yet.


Enable / Disable Outlook 2007 Rules

As a Blackberry user, one of my pain-points is with the pst files. Here is how it goes. Let's say Outlook is open and I get an e-mail, my rules process it and move it to one of the pst folders. Problem is that I don't get it in my BlackBerry.

Of course, if outlook was closed, or if the rules were not processed, that message would end up in my BlackBerry. As I want to keep outlook open, I have to disable the rules. There is no manual way of quickly doing this. If you look at Outlook Rules > Run Rules, you can not, for example, select all with Ctrl+a. You have to click and select each one of them. Painful!

So, I decided to create a macro, that would automatically disable the rules, or enable & run them. Idea is that in the morning, I will keep the rules disabled so that I will get them in my BB, and time to time I will run enable script to move them to psts.

Below is the code. In Outlook, you can
* press Alt+F11
* Expand Project1 (VbaProject.OTM)
* Expand Microsoft Office Outlook Objects
* double click ThisOutlookSession
and paste the code in there.

Then you can simply Press Alt+F8 and chose the action...

Sub DisableAllRules()
Dim colRules As Outlook.Rules
Dim oRule As Outlook.Rule
Dim count As Integer
Dim ruleList As String
'On Error Resume Next

'Get Rules from Session.DefaultStore object
Set colRules = Application.Session.DefaultStore.GetRules

' iterate all the rules
For Each oRule In colRules
oRule.Enabled = False
count = count + 1
ruleList = ruleList & vbCrLf & count & ". " & oRule.Name


' tell the user what you did
ruleList = "These rules were enabled: " & vbCrLf & ruleList
MsgBox ruleList, vbInformation, "Macro: DisableAllRules"

Set colRules = Nothing
Set oRule = Nothing
End Sub

Sub Enable_Run_AllRules()
Dim colRules As Outlook.Rules
Dim oRule As Outlook.Rule
Dim count As Integer
Dim ruleList As String
'On Error Resume Next

'Get Rules from Session.DefaultStore object
Set colRules = Application.Session.DefaultStore.GetRules

' iterate all the rules
For Each oRule In colRules
oRule.Enabled = True
oRule.Execute ShowProgress:=True
count = count + 1
ruleList = ruleList & vbCrLf & count & ". " & oRule.Name


' tell the user what you did
ruleList = "These rules were enabled: " & vbCrLf & ruleList
MsgBox ruleList, vbInformation, "Macro: EnableAllRules"

Set colRules = Nothing
Set oRule = Nothing
End Sub


Rounded Corners with CSS

I was looking for a way to create rounded corners without using images. I came across "Nifty Corners Cube" which does exactly that and more.


Digg - The Pictures Section!

I check Technology Section of at least a couple of times daily. I am not sure exactly what purpose the new picture site will serve but it's another way of 'sharing', which is a good thing.

Heh, this site turned out to be a 'rogue' one :) Still... I like the idea.

read more | digg story


Install Ubuntu On Windows - WUBI

I saw an article about installing Ubuntu on Windows at Ubuntu-Unleashed Blog. It talks about an open source project called "WUBI".

Premise is very simple: You install an application called Wubi on Windows XP/Vista which uses an "alternate" (text based) Ubuntu ISO file to install Ubuntu in the windows partition in a 'single file' and give you an option to boot into it.

What does that mean? You do not need to have separate partitions to install linux/windows. It installs necessary drivers to access NTFS share, and does pretty cool stuff like importing your favorites/booksmarks.

When I was testing the application, which you can download via this link, it could not connect to a download site for ubuntu alternate image. So, I checked c:\wubi\install\ubuntu-7.04-alternate-i386.iso.metalink and used one of the US sites to download it.

I copied both the alternate image and wubi executable to the same directory and then ran the executable. GUI part is quick, actual installation takes sometime. It's advised to defrag your machine prior to installing it.

This is a cool idea and I hope it gets official acceptance from Ubuntu! Check out Wubi Forums if you are interested.


Lifehacker's Top 10 Gnome Desktop Tweaks

The default desktop environment for Linux users, Gnome, is fast, organized and very easy to learn. But Gnome is also very powerful and highly customizable. Today's top 10 lists the various ways you can tweak Nautilus and the Gnome desktop to turn Linux into a productivity powerhouse.

read more | digg story


Who owns what

Above picture, which lists some of the companies bought a few Media conglamorate, was put together by Amy Webb and is getting circulated a lot these days. It gives an idea about how much of Internet these few companies own.


Online Storage finally taking shape

Just want to note this article about Online Storage and what big 3 (Google, Microsoft, Apple) are doing about it. I think online storage makes perfect sense now that we have faster internet connection.

I only tried Microsoft's Windows Live SkyDrive and it looks pretty good but of course 500MB is 'nothing' if you seriously want to keep your files online. It maybe enough if you only want to keep 'some' files


A (much needed) update for Vista

Today, when I saw MS KB938194 titled "An update is available that improves the compatibility and reliability of Windows Vista" and look at the issues it resolved, it reminded me of my experience with an ATI card when I moved to Vista:

A couple of months ago I bought a nice (=expensive) ATI all in wonder X800 video card and it worked perfectly fine under Windows XP when I was playing World of Warcraft (WoW). Then, I installed Vista. All seemed fine for a week or so and then hell broke loose...

At first, I would not be able to play more WoW than 5 minutes. It would freeze and I had to reboot. Then it got worse so that I could not even play 30 secs. I gave up and started to use my other PC to play the game.

It got even worse when Vista started to freeze even when I am not playing a game but just playing any video file. At some point, my pc was totally unusable as animations were too much to display.

One of these days, I saw a sign that CompUSA shop near my house was getting closing and there was a close-out sale. I bought ATI X1600 Pro & retired the problematic one but promised myself to test it out on my Windows XP box to see if the problem would present itself there too...

Read this article for more on Windows Vista issues and possible fixes coming out...


Vista UAC is just trouble

I am sorry to say this but Vista UAC is broken! I understand the concept, and I understand where Microsoft is coming from. In fact, I felt quite comfortable the way Ubuntu has implemented basically the same idea. But it is just painful in Vista.

I tried to work with it but got fed up soon. So, I disabled it using Local Group Policy. And then, my problems started. I did not realize it until today but UAC was the reason behind a couple of mysterious issues I was having. A few recent examples...

* NTFS permissions are all screwed up. Although my user account is in Administrators/backup operators groups, I sometimes can not access my personal folders. Then, I have actually blogged this here, so I wont go into details...

* My backup process got broken. I loved rsync in unix world and the closest thing I have in Vista is of course good old Robocopy. I already had some backup scripts that would take daily back ups between my various disks and PCs. Time to time, I would get mysterious errors like "ERROR 5 (0x00000005) Changing File Attributes"...

* Windows update would never install 'any' update. It kept on downloading the files and then reported errors but never offered any explanation why.

Finally, I suspected that UAC was not fully disabled. I saw a nicely written article and used msconfig method (Run msconfig > Tools > Disable UAC).

And guess what? Suddenly all looks good now :)

Vista fails to boot

My vista ultimate crushed today for no apparent reason. As if that's not bad enough, Vista could not be loaded. Instead, I was stuck at the screen.

Windows failed to start. A recent hardware or software change might be the cause. To Fix the problem:

1. Insert your Windows installation disc and restart your computer
2. Choose your language settings, and then click "Next"
3. Click "Repair your computer"

If you do not have this disc, contact your system administrator or computer manufacturer for assistance.

File: \Windows\system32\winload.exe

Status: 0x000000e

Info: The selected entry could not be loaded because the application is missing or corrupt

Resolution: Simple, I simply unplugged the exterior Sony DVD burner. A funny fact was that simple reboot did not fix the issue but I shutdown the PC completely and then powered it on.


NYC Subway Map

Just blogging this link of a site that has overlayed NYC subway and NJ Path information on Google maps.

A good feature is that, you can view all the trains passing thru a station when you move the mouse over the nodes.

Not a new idea, but good implementation.


Outlook hangs due to Search Issue

I love to keep all my e-mails. So, I have huge outlook .pst files dedicated to some some active lists that I subscribed more than 10 years ago. Recently, I noticed that instant search in Outlook 2007 was not functioning properly. It would never find anything.

I checked the instant search index status (Tools > Instant Search > Indexing Status). It said something like
"Outlook is currently indexing your items." 1 item remaining in Inbox 150000 items remaining across all open mailboxes

It was clear that instant search was not working properly. So I checked "Windows Search" service by typing "Start > Run > services.msc"
Services was up and running...

Then I checked "Control Panel > Indexing Options". I decided to rebuild the index. So, I clicked "Indexing Options > Advanced > Rebuild" and changed Index location to a folder in a different drive that I usually use for backups.

Things went totally haywire after that :( Whenever I tried to check Indexing Options, it gave me messages like "Retrieving windows Search status" or "Windows search is performing maintenance". Restarting service did not help.

To add to my troubles, Outlook 2007 stopped working. I was able to start it in Safe Mode but it would not start in regular mode and just freeze during startup.

I started Outlook in safe mode and then ran Office diagnostics (Outlook > Help > Office Diagnostics), which found no issues. Google searches did not result in anything useful. Finally, I used Office 2007 CD to "repair" to no avail.

At this point I was not sure why Outlook was not working but because all this stuff did not happen the same day, at first I did not suspect them to be related. In fact, after an unexpected power outage, some Vista permissions were screwed up and I was thinking that issue could be related to .pst folder permissions.

Then it downed on me! I disabled/stopped Windows Search and then started Outlook. Puff! It launched without any issues. Basically, Outlook 2007 was detecting that Windows Search was not available,and disabling Instant Search.

I did a little bit more search on how to build index and found this MSDN thread:

"Set the registry value HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Search\SetupCompletedSuccessfully to 0 and try restarting the Windows Search service."

I did and it worked. Windows Search started indexing items properly and Outlook 2007 launched without a hitch. Problem solved.

For reference, below is what I saw in the Event viewer when index was corrupted and restarting service would not help:

Log Name: Application
Source: Microsoft-Windows-Search
Date: 7/14/2007 4:28:59 PM
Event ID: 3026
Task Category: Gatherer
Level: Error
Advise Status Change failed. The system is probably low on resources. Free up resources and restart the service.

Context: Windows Application, SystemIndex Catalog

The content index server cannot update or access information because of a database error. Stop and restart the search service. If the problem persists, reset and recrawl the content index. In some cases it may be necessary to delete and recreate the content index. (0x8004117f)


Vista snipping tool error

I had an interesting issue with my Vista build today. Well, I have to disclose that this is basically a preview build that our engineering team is testing in the company. I was trying to launch Snipping Tool and received an error:

The Snipping Tool is not working on your computer right now. Restart your computer, and then try again. If the problem persists, contact your system administrator.

Sure enough, rebooting the machine did not help. I checked the event viewer and noticed that a warning gets logged everytime I try to start it:

Log Name: Application
Source: Microsoft-Windows-SoftwareRestrictionPolicies
Date: 7/12/2007 3:15:25 PM
Event ID: 866
Access to C:\Windows\SYSTEM32\WISPTIS.EXE has been restricted by your Administrator by location with policy rule {F8509577-AE57-4057-B256-2929FCC0931A} placed on path *WISPTIS.exe.

So, what's this Wisptis? "Windows Ink Services Platform Tablet Input Subsystem".
I ran rsop.msc to confirm that it was listed under

"Computer Configuration" > "Windows Settings" > "Security Settings" > "Software Restriction Policies" > "Additional Rules"

Why would snipping tool need Wisptis.exe is beyond me.

[Edit: 04/04/2008]
I've scraped the preview build long time ago and I use ultimate version for sometime. However, I get comment from people who still see the issue I mentioned above. I got two comments from people who confirmed that running "Office Diagnostics", however irrelevant it seems, fixed the issue for them.

It makes me very happy to see comments from people who reach this blog and either find or suggest solutions to problems. Thank you all!


Running PowerShell Scripts

When I read "Running windows PowerShell Scripts" on Microsoft technet, I wanted blog it. It's a long article. I am kinda disillusioned with PSH at this point :(

Some excerpts:

To summarize, here’s how you run from scripts from within Windows PowerShell:
• Make sure you’ve changed your execution policy. By default, PowerShell won’t run scripts at all, no matter how you specify the path.
• To run a script, specify the entire file path, or either: 1) use the .\ notation to run a script in the current directory or 2) put the folder where the script resides in your Windows path.
• If your file path includes blank spaces, enclose the path in double quote marks and preface the path with an ampersand.
And, yes, that all takes some getting used to. However, you will get used to it. (To make life easier for you, we recommend that you keep all your scripts in one folder, such as C:\Scripts, and add that folder to your Windows path.)

We realize that it’s been awhile, but way back at the start of this article we tried running a Windows PowerShell script by double-clicking a .PS1 file. That didn’t go quite the way we had hoped: instead of running the script all we managed to do was open the script file in Notepad. Interestingly enough, that’s the way it’s supposed to work: as a security measure you can’t start a PowerShell script by double-clicking a .PS1 file. So apparently that means that you do have to start PowerShell before you can run a PowerShell script.

In a somewhat roundabout way, that’s technically true. However, that doesn’t mean that you can’t start a PowerShell script from a shortcut or from the Run dialog box; likewise you can run a PowerShell script as a scheduled task.

The secret? Instead of calling the script you need to call the PowerShell executable file, and then pass the script path as an argument to PowerShell.exe. For example, in the Run dialog box you might type a command like powershell.exe –noexit c:\scripts\test.


Technet Webcast: Windows Hang and Crash Dump Analysis by Mark Russinovich

This is a great presentation from Mark Russinovich on BSODs.

Learn to analyze Microsoft Windows crash dumps, diagnose the cause, pinpoint a solution, and resolve the problem. Intended for system administrators, this webcast explains how system crashes occur and what happens when you reboot a crashed system. We lead you through the crash dump analysis process step by step, introducing the latest tools from Microsoft and handy tricks for isolating the cause of a crash.

Presenter: Mark Russinovich, Chief Software Architect and Cofounder, Winternals Software

Mark Russinovich is chief software architect and cofounder of Winternals Software, a company that specializes in advanced systems software for Microsoft Windows. He is coauthor of Windows Internals, 4th Edition (Microsoft Press, 2004), a Microsoft MVP, and he contributes to the Sysinternals tools at, including Process Explorer, Filemon, and Regmon. Mark has a PhD in computer engineering from Carnegie Mellon University and is a senior contributing editor for Windows IT Pro Magazine.

To avoid possible problems, we suggest you temporarily disable pop-up blocker software before viewing the webcast.

Now that Tech-Ed is over, there are a lot of webcasts available. You can view Other sessions from Tech·Ed 2006 Webcasts: Power to the Pros.

View other sessions from Tech·Ed 2006 Webcasts: Power to the Pros.


25 Most Popular Blogs June 2007 (Ranked By 5 Traffic Data Sources)

A complete list of the top 25 most popular blogs ranked by a combination of Inbound Links (Yahoo Site Explorer), RSS Subscribers (Feedburner), Alexa Rank and Compete and Quantcast traffic data. The data gives you a real insight into these blogs success which will allow you to judge the relative success of your own blog.

read more | digg story


Hack Your Router

Umm, well this is 'old news' that I only became aware of thanks to a colleague. There is a LifeHacker article about boosting router signal as well as adding tons of features to it for some make/model but especially Linksys WRT54GL Wireless router

Here is the link to the article.


Microsoft Surface

The launch of Microsoft Surface marks the beginning of a new technology category and a user-interface revolution. Surface, Microsoft’s first surface computer, provides effortless interaction with digital content through natural hand gestures, touch and physical objects. Surface computing breaks down traditional barriers between people and technology.

read more digg story

Google Maps StreetView

Google Maps have a new feature and may be the best one I've seen: Street view. It's available in limited content now but you can click a street and look at a 360 degrees picture of the street! That's an awesome feature and can be extremely useful!

You can have an idea what the street looks like. You can use the arrows to go in all directions. I can't wait to see coverage getting wider. Check out the Demo.


The Ultimate Linux Reference Guide for Newbies

Very nice and complete linux commands reference:

read more | digg story


Google 2.0 Unleashed Today: Universal Search, Invisible Tabs, and More

Google is undertaking the most radical change to its search results ever, introducing a "Universal Search" system that will blend listings from its news, video, images, local and book search engines among those it gathers from crawling web pages.

read more | digg story


Ubuntu Unleashed (Free eBook)

Incorporating an advanced approach to presenting information about Ubuntu, Ubuntu Unleashed aims to provide the best and latest information that intermediate to advanced Linux users need to know about installation, configuration, system administration, server operations, and security.

read more | digg story


Ubuntu 7.04 (Feisty Fawn) has officially been released!

The beta and the wait is over. Ubuntu 7.04 has been released and is available for immediate download.


Ubuntu feisty fawn (7.04) finally available on shipit for free

Canonical started to send free cd-s of ubuntu 7.04 feisty fawn. simply go to and login with your Launchpad ( id to request the CDs

read more | digg story


IIS Permission Denied Error

I had some asp pages that worked fine on IIS5/w2K but gave me an error like below on IIS6/W2K3.

Microsoft VBScript runtime error '800a0046'
Permission denied
/SelfService/e360.asp, line 69

I searched thru MS site but could not come up with anything. I found my answer on ASP emporium site.

Line 69 has an OpenTextFile command with option 8 to modify and IUSR_ did not have rights to write into that file/folder. To fix it,

- Created a local user acc
- IIS Manager > Browse to Web sites > Default Web Site >> Properties > Directory Security > Edit > Set User name:MachineName\, Password: password
- Give Write Permission to on C:\Inetpub\wwwroot


Google Browser Sync for Firefox

Google Browser Sync for Firefox is an extension that continuously synchronizes your browser settings – including bookmarks, history, persistent cookies, and saved passwords – across your computers. It also allows you to restore open tabs and windows across different machines and browser sessions. For more info, please visit our FAQ.

It's pretty easy to set up.


Vista Auto Logon

According to: If you have a single user without password, then he gets logged on automatically after restart.
Not recommended! Of course, anyone with sufficient access to read your registry, can read your password in plain text if you set it up this way…

Here’s the procedure:
Open Regedit,
  • Drill down to HKLM/Software/Microsoft/Windows NT/CurrentVersion/Winlogon,
  • Find the “AutoAdminLogon” value, and change it to 1. Enter the following items as new string values: “DefaultUserName”, and “DefaultPassword”.
  • Set the value of DefaultUserName to be the username that you want to autologin, and set the value of DefaultPassword to be that user’s password.


Cool javascript trick

Go to any web site, preferably with lots of pics. copy/paste the following to the address bar and hit enter.

javascript:R=0; x1=.1; y1=.05; x2=.25; y2=.24; x3=1.6; y3=.24; x4=300; y4=200; x5=300; y5=200; DI=document.images; DIL=DI.length; function A(){for(i=0; i-DIL; i++){DIS=DI[ i ].style; DIS.position='absolute'; DIS.left=Math.sin(R*x1+i*x2+x3)*x4+x5;*y1+i*y2+y3)*y4+y5}R++}setInterval('A()',5); void(0);

Here is the original Digg article.