Cant see the desktop? which means the computer boots up properly.. But u cant see the wallpaper nor any icons? am i right?..
The "....... has been cacelled by the Administrator" is a very common symptom of a pesty virus running around through memory sticks these days. Almost impossible to recover windows even after the infection has been removed.
I can suggest something but dont know whether it will help. Since u can get to taskmanager, Click NEW TASK in task manager and type sfc /scannow you will need a Windows XP CD as it will ask for one.
Another attempt would be to keep pressing F8 while the computer is starting up till you get to a boot choices menu. Select Last known good configuration of Windows
If that doesnt work, agian get into the same screen by pressing F8 at boot and select Safemode. If u see your desktop in Safemode try to do a virus scan.
Sounds like a virus attack. Your choice now is what you do to remove the virus. Some of the latest virus programs mess so much with Windows that it may never be fixed.
option 1 try to fix the problem. Google Avira Rescue-CD and download the program
But, first I would try a bootable antivirus product called AVIRA Rescue-CD It comes as a download that when executed burns a bootable CD on your computer. You then change the boot order in the BIOS to start the computer from the CD drive. The Linux based CD is able to find and optionally remove or rename various virus and malware programs. Out of the box it is in German - you must click on the Union-Jack flag to change the interface to English. The default options just alert you when it finds a problem. You must go to the configuration settings tab and order it to remove the offending programs.
The only sure way out of your mess is a complete Windows re-install. BUT, you loose all your data and programs.