Task manager/registry editor disaabled by adm

Hello,
i am not able to open task manager & registry editor. getting error it is disabled by your administrator. i have reinstalled xp more than 10 times by different cd's. still nothing happens. i tried all the steps found on google, still nogo. after applying scripts, it gets enabled but again it gets disabled. sometimes the system also restarts by itself. please help.

jazzyz@ymail.com