Many discover this feature as they reduce the admin account to just one and then that account fails.
You didn't tell enough. Missing details about the login failure.
But let's tackle the most common fixes.
1. The password is not accepted.
Fix: NTPASSWD (that's it, google that.)
2. The account may work in SAFE MODE
Fix: Do that, create a new ADMIN account fast.
3. The CORRUPT PROFILE issue.
Fix: NONE!!! Proof? Read http://support.microsoft.com/kb/811151 and notice Microsoft does not hint or offer a way to fix this one.
loss of power to the house has resulted in loosing all administrative accounts & profiles. Cant log into anything on the admin section. Only 1 acount acces and has no admin privlages. Have been told it may possibly be a damaged user profile. Need help on how to repair this so i can log on . Thanks PS its a dell optiplex gx260 :with pent 4 & windows xp prof., version 2002, service pack 3