Administrators account lost...

[Sue]

I have somehow lost my administrators account in windows
XP and I am unable to access it. I have created a guest
to log on. When i try to access some of my programs or
to restore anything I recieve this message. You do not
have sufficient security privileges to restore your
system. Please contact your administrator, or log out
and log in again as an administrator and try again. Does
anyone know where I can find my administrator account, it
not visable in user accounts.