Due to some virsu attck, I am not able to open the "Task manager","run" command, 'folder preference' rights etc. I have lost the administrator rights.

Plz help me to sort this

Do you get an error that the Administrator has disabled the Task Manager?

If so see this:

http://windowsxp.mvps.org/Taskmanager_error.htm

If the issue is other than that please follow the instructions in this thread and post a HijackThis log in the HijackThis section (not here please):

http://www.d-a-l.com/help/showthread.php?t=32403