Check thoroughly for any viruses, which might have caused these conditions and if the problems persist, try these registry edits.
http://www.kellys-korner-xp.com/xp_tweaks.htm
Line 154 (Right column) - Remove "All Programs" from Start Menu -
Undo
Line 256 (Left column) -
Restore the Control Panel - Disable : Current , Local, Both
Line 51 (Right column) -
Enable the Task Manager - Disable Task Manager
You should back up the registry beforehand, and afterwards, if everything is ok, for easy restoration later.
http://support.microsoft.com/kb/322756