Group Policy Notes
Where to look for policies that have been applied to the user and computer:
Computer: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Group Policy\History
User:HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Group Policy\History
Group Policy Preferences vs Group Policies. Taken from the Preferences guide: https://www.microsoft.com/downloads/en/confirmation.aspx?FamilyID=42e30e3f-6f01-4610-9d6e-f6e0fb7a0790&DisplayLang=en
Troubleshooting
Descriptions of Group Policy operational logs fields (Vista +): https://technet.microsoft.com/en-us/library/cc749336%28WS.10%29.aspx
Export the operational log to old school log format: gplogview -o gpevents.txt (download for gplogview: https://www.microsoft.com/downloads/en/details.aspx?FamilyId=BCFB1955-CA1D-4F00-9CFF-6F541BAD4563&displaylang=en)
Reading Userenv (XP/2003): https://technet.microsoft.com/en-us/library/cc786775%28WS.10%29.aspx