gpscript.exe is the group policy script executable in Vista. It *sounds like* you've got problems with your group policies on the Windows side, nothing to do with GPRESULT tool to see what policies are being applied and then you'll probably have to go through the policies to eliminate the problem.
See here (
http://www.microsoft.com/windowsxp/using/setup/expert/gpresults.mspx) on how to use GPRESULT.
Hope this helps.