Administrator account no longer administrator

pvr

I am running Windows XP SP2. There is only one user account on my PC which is the Administrator account. Suddenly it is not being recognised as an Administrator account as it won't let me do things like run Task Manager and when I click Start the Shutdown option has disappeared and only the Log Off option is there. When I go to Control Panel and User Accounts my account is listed there as Computer Administrator.

How has this happened and how can I resolve this?

closed

normal accounts can do all of those things, run a malwarebytes check, or use system restore, and or/run chkdsk c: /F

Hammyman

And to the OP, your account is a member of the Administrators Group and not the Administrator account - the two are not the same nor do they have the same privilidges.