MMC User policies causing problems!!

I do hope there is someone here who can help me before I throw this PC out of my window!! I have been trying to "fix" this problem with my Admin Tools since I ran a WinXP Tweak program. I don't know exactly what I did but now I cannot access the Computer Management, Services or anything in Admin Tools. I keep getting an error "The user polices prevent MMC from creating a snap-in" I have no clue what a snap-in is; all I know is I cannot use my Admin tools and some of my processes will not run at all! So, if anyone can advise, help me before I pull every strand of hair out, I would greatly appreciate it!

Thanks,
Michele