group policy in xp

I was effecting some group polices.However, when I went back to “run” and type gpedit.msc I got the following message
Snap-in failed to initialize
Name: Group Policy
CLID: {8FCB734-A0E1-11D1-A7D3-0000F87571E3}
I cannot get into Local security policy either.
i am log on as the administrator