I have just found a new account on my home computer called, ASP.NET.machine A it was a password protected administrator account!!

My wifes account which was a Limited user account with no password has changed to an Administrator account with no password.

I have now deleted the ASP.net account and changed my wifes account to limited and made her put a password on it.

Does anyone have any idea how a new adim account can just appear?
Do I have to do anything else except delete this account?

Could any software have created this account, or has someone remotley created it?

I am running WIN XP Pro.

TIA!!