[/color][color=black]I lost my Control Panel because of the virus TrojanKilAV. I got rid of the virus but can't get my Control Panel back. I get the message, "This operation has been canceled due to restrictions in effect on this computer. Please contact your system administrator." How do I get my Control Panel back which is now labeled, "Set program access and defaults"?  

Read this Microsoft article.
http://support.microsoft.com/kb/221153/
Although it doesn't specifically include WinXP, you can try the fix for WinNT.
XP is a later version of WinNT and Win2k, so the same fix could work for it.
Good luck.