User Environment Debugging

I had not used this is so long i had forgotten where the key lives.
This windows debugging technique is required if you have slow logon or logoff issues and want to try and isolate the problem area. The output will show you the timings for each part of the logon process.

HKLM\Software\Microsoft\Windows NT\Currentversion\Winlogon
UserEnvDebugLevel

Set to 10002 (REG_DWORD)

The output gets placed by default in C:\WINDOWS\Debug\UserMode\userenv.log

A tool called policy reporter is very handy for reading the log files.