Can't uninstall managed application

I want to uninstall an application that I installed via group policy to uninstall. I have unassigned it from the computer account and when the computr is booting then it says that it is trying to uninstall the application. When I am getting to the desktop and check the application log then it says the application failed to uninstall and I am getting the below errors:

Event Type: Error
Event Source: MsiInstaller
Event Category: None
Event ID: 11306
Date: 1/6/2005
Time: 9:36:43 AM
User: NT AUTHORITY\SYSTEM
Computer: RED-CFOSTER
Description:
Product: PKZip -- Error 1306. Another application has exclusive access to
the file 'C:\Windows\System32\wbem\Repository\FS\INDEX.MAP'. Please shut
down all other applications, then click Retry.

Event Type: Information
Event Source: MsiInstaller
Event Category: None
Event ID: 11725
Date: 1/6/2005
Time: 9:36:47 AM
User: NT AUTHORITY\SYSTEM
Computer: RED-CFOSTER
Description:
Product: PKZip -- Removal failed.

Did you try to uninstall the program in Safe Mode? Check the below link on how to boot in Safe Mode:
http://support.microsoft.com/kb/315222

I did try that long time back but it tells me that the installer service is not able to perform the action in safe mode. I am sure that it is because the application was installed via Group Policy.

Add/Remove 4Good can uninstall stubborn applications to keep your system clean. It works pretty fine for me. So you can give it a try!