Question : Task Manager and regedit 'disabled by administrator', unable to access Safe Mode, Antivirus deactivated

I have a serious problem here. This is note my notebook, but, I'm in charge of fixing it. So, I do not one what brought about this problem.

Here's the problem with this notebook.

- Task Manager dimmed out.
- Regedit  - 'Registry editing has been disabled by your administrator'
- Cannot Boot into Safe Mode.
- Antivirus program deactivated/uninstalled

The following still can open
- Folder Option
- Services.msc
- msconfig
- System Restore (have not tried the restoring yet).

Have tried using tweek from
http://www.kellys-korner-xp.com/xp_tweaks.htm
But does not work.

Have tried installing Clamwin, but the moment it finish installed, it disappear from the system tray and I cannot load it. Symantec was totally gone. I checked 'Add and Remove Program' and only found 'Live Update' for Symantec, but, not the software itself. Clamwin was still in the list because the uninstaller still in the folder. But the Clamwin exe file is also missing from it's folder.

Scanning with Microsoft Windows Malicious Software Removal Tool now, but, have not found any file.

Answer : Task Manager and regedit 'disabled by administrator', unable to access Safe Mode, Antivirus deactivated

Also try an online scan through ESET: http://www.eset.com/online-scanner
There's also a very useful utility called smitfraudfix that does a marvelous job of clearing out stuff like this. (Particularly if you also have a notice in the task bar telling you to install some antivirus)
http://siri.geekstogo.com/SmitfraudFix.php

And just for good measure, try to run gpedit.msc if it opens, navigate to User Configuration -> Administrative Templates -> System and check the status of the "Prevent access to registry editing tools" entry. If it's enabled, you can disable it to get use of regedit back. Also check under Logon/Logoff under System to see if Disable Task Manager has been enabled.

Also look at this option for getting safe mode boot back: http://www.theeldergeek.com/add_safe_mode_to_boot_menu.htm