Unable to delete printer driver from Windows 7

In my case user was running on windows 7 x86 sp1, and was complaining that he can't print because printers doesn't exists on his computer. Printers should be installed using group policy preferences, so I have started to troubleshoot the problem. Printer spooler was stopped, and that was the reason why the user doesn't see printers in control panel. Printer spooler was stopping whenever group policy for installing printers was applying. So, I wanted to delete all unnecessary printer drivers that were installed. After opening Print Management mmc there were a lot of printers drivers that were not in use, and I started to remove drivers packages that were not in use. For the most of them removing was running smoothly, but there was one that was refusing to delete complaining that :

"The specified printer driver is currently in use. Failed to remove package ..."

I have tried a lot of the suggested solutions, but none of them helped me to delete the driver package. The only way that I have succeeded to delete the driver package was to rename the print processor from registry in my case HKLM\SYSTEM\CurrentControlSet\Control\Print\Environments\Windows NT x86\Print Processors\ , and then delete the driver package from print management console.
Printers defined in GPO have successfully installed, and user was able to print documents.

Unable to reboot remote system

In my case remote workstation was XP and a user was unable to connect using remote desktop client, after disconnecting from the same computer couple of minutes ago. I have decided to initiate reboot of the client workstation using:

shutdown /f /r /m \\computername,

but the machine was hung up, and I tried to initiate same command again but the response was :

A system shutdown is in progress.(1115)

 

After waiting few more minutes the client workstation was not rebooted.

Because there was no one around the client machine to see what's happening on the monitor, and the user desperately needed to establish remote connection to the client workstation I have decided to kill the winlogon process. Using PSKill from PSTools suite I have executed:

pskill -t \\computername winlogon

and the remote workstation was rebooted. Note that killing winlogon process is nearly the same as pulling the plug on the machine.