My user disappeard from the welcome screen. It have administrative privileges which i cannot remove because it is built-in account. The only user that appear is the administrator account which have administrators privileges .Also I want to remove the administrators privileges of the user account i am working with.

Lost or Corrupt User Profile http://www.kellys-korner-xp.com/xp_... Create a new account/administrator profile and log in. Then go to C:\Documents and Settings\[Previous User Profile] and copy all folders to: C:\Documents and Settings\[New User Profile]. Then reboot. How to copy data from a corrupted user profile to a new profile http://support.microsoft.com/defaul... More here. xp user privileges http://www.google.com.au/search?hl=...

In C:\Documents and Settings\[New User Profile] and C:\Documents and Settings\[Previous User Profile]. there is not file named of the previouse user prifile