WinXP: ADmin login gone or MIA

> Hi All,
> I've been using my XP Administrator account for a while, prior to
> adding users on this machine. After I added my first user, the
> Administrator login prompt went away. Now I know this is a "feature"
> but how do I log back into my administrator account.
>
> 1.) Under /documents and settings/ the account info is still there.
> 2.) Tthe 1st user account also has admin privilages.
> 3.) From Cntrl Pnl/Users, I cant see the Administrator as a user
> account.
>
> Thanks,
>
> aaron