Very restricted access to programs in XP (home)

I was trying to adjust my security settings and I've managed to lock myself out of all programs, except Internet Explorer. I have Norton Antivirus 2006, Norton Systemworks (Basic) and am running XP (Home). I am logged on as Administrator, can see my usual Desktop, but not my usual array of icons at the bottom right end of Taskbar. All the shortcuts on the desktop (except I.E. ) and all the programs in Start-All Programs-whatever give me the same message in a box titled RESTRICTIONS:" This operation has been cancelled due to restrictions in effect on this computer. Please contact your system administrator." Even when I try and download something it will seem to download O.K., but on the machine trying to install the download the same dreaded message appears! I can access the Control Panel but when I try to change the Security Settings I get the same message. I cannot Add/Remove Programs either.
My machine is a P4 with 1Gb RAM, ATI Radeon, 160Gb H.D. running XP(Home).
I know I've been stupid somewhere along the line, but hope someone more knowledgable out there can help?

 

Were you messing with Norton's security settings or Windows?
You could try a Repair Install
http://www.microsoft.com/windowsxp/using/helpandsupport/learnmore/tips/doug92.mspx
NOTE:If you can, backup any necessary files in case they get erased during the format.

A Repair Install will replace the system files with the files on the XP CD used for the Repair Install. It will leave your applications and settings intact, but Windows updates will need to be reapplied.

A Repair Install will replace files altered by adware and malware, but will not fix an adware, malware problem.

 

Thanks Bladesofhalo. I searched through similar threads and tried Safe Mode boot and then a System Restore. This did the trick! Thanks anyway. Bob Roberts