Fixing quser access is denied error

Daily PowerShell tips from are a great way to learn PowerShell tips and tricks. They sent a tip yesterday about 'quser'. If you have been around for a while, you may remember that command. A long long time ago, Citrix helped Microsoft to create 'Terminal Server'. They also created some 'q****' commands.

If you go into your system32 directory and list executables that start with q, you will some others, like qwinsta.exe and qprocess.exe, as well as quser.exe Microsoft kept these executables ever since.

I am familiar with them, because many years ago I had written a perl application to monitor Citrix Servers and these commands came handy at the time.

Anyway, PowerShell tip yesterday was about finding out logged on user:

PS H:\> quser  
  >adil              console             1  Active      none   1/15/2014 11:35 AM PS 

H:\> (quser) -replace '\s{2,}',','|ConvertFrom-Csv
 SERNAME    : >adil
ID          : 1
STATE       : Active
IDLE TIME   : none
LOGON TIME  : 1/15/2014 11:35 AM

The first command shows what you would have seen by running the command on the current machine, and Tobias Weltner's tip shows us how to first replace 2 or more spaces with ',' and then, use ConvertFrom-CSV cmdlet to convert string into a reusable PowerShell Object (PSObject).

Today, there was a follow up on the tip to find out who logged on on a remote computer, using /server parameter. One of my colleagues tried it and and reported that it was not working for her.

Error 0x000006BA enumerating sessionnames
Error [1722]: The RPC server is unavailable.

The first line of error suggested that it was a permissions issue, but she was an admin on the remoe windows 7 box.
The second line was telling us that the remote machine was not responding to Remote Procedure Call (RPC).

So, to fix this, we needed to enable RemoteRPC calls in the registry of the remote machine.
PS H:\> invoke-command -computername adil-w7x32vm2 -Command { set-itemproperty 'HKLM:\SYSTEM\CurrentControlSet\Control\Terminal Server' -Name AllowRemoteRPC  -Value 0x1 -Force }

 And once the RemoteRPC is allowed, query goes through without any errors.

PS H:\> (quser /server:adil-w7x32vm2) -replace '\s{2,}',','|ConvertFrom-Csv

  USERNAME    : testuser
  SESSIONNAME : console
  ID          : 3
  STATE       : Active
  IDLE TIME   : none
  LOGON TIME  : 1/15/2014 10:29 AM
 Note that, you migh also use the following command to connect to remote registry and change the setting, in case you cannot use invoke-command:

reg add "\\ComputerName\HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server" /v AllowRemoteRPC /t Reg_Dword /d 0x1 /f

And query to make sure the change took place:

PS H:\> reg query "\\adil-w7x32vm2\HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server" /v AllowRemoteRPC

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server

    AllowRemoteRPC    REG_DWORD    0x1
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