How to create administrator rights and privileges with xp

I am running a 2k server with a domain. System is old and slow, so I wanted to free up some files, I added several xp pro boxes to the system with plans of mapping a drive on one of the computers and allowing several users from the domain to access this drive. We will refer to Comp1 as xp computer with the drive everyone will access and comp2 as my computer.In doing so I realized that if I logon to the domain using my computer (comp2) and its original administrator account it works fine but if I logon using a different user that I created and gave it administrator privilages I still have to logon to the mapped drive to use it or view its contents why help