How to Enable Application Management Logs

When a program that is deployed through Group Policy is not installed correctly on a client computer, a log file can be generated that records the steps of the Group Policy Application Deployment component leading up to the unsuccessful installation. This information, in conjunction with logging from the Windows Installer service, can be very helpful in determining the cause of the problem.

KB article: 246509
Public URL: 246509 Troubleshooting Program Deployment By Using Verbose Logging
http://support.microsoft.com/?id=246509

Value Path: HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Diagnostics
Value Name: AppMgmtDebugLevel
Value Type: REG_DWORD
Value Data: 4B (hex)
Note: You may need to create the Diagnostics key.
Output: %systemroot%\debug\usermode\appmgmt.log