ok heres the deal

im on a LAN with a desktop and a laptop
i set-up both computers, so i know both admin passwords

so heres my question

both winxp btw

how can i get full root/admin accesss from one to the other?

ive gone through the netbios, but only a few programs are being shared

(and im trying to more or less "break into" this computer, wihtout
sharing my c:/ drive on it-- im doing this fora challenge)

so im wondering, what are my options