i noticed my task manager was disabled. i tried to use 'start - run - regedit' and found registry is diabled.
i found the answer from the forum to enable task manager using
"click "Start" and then "Run"
type in the following...
REG add HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableTaskMgr /t REG_DWORD /d 0 /f
click ok".
it works..
So, i solved task manager problem
but
still i have registry key problem. 'gpedit' is also not working. i received error ' windows can not find gpedit.'