has no one helped you yet?
adobe's activation has nothing to do with admin rights.
Make certain you have full admin rights.
Did cs2 install correctly?
what about machine specs?
are you certain that adobe isnt saying your machine doesnt have the proper system configuration.
Adobe software checks alot of things before installing.
you need xp sp2
you need 1 gb of ram
you need 5gb hd space.
If you haven't resolved this then get me more information about the machine and will photoshop run in the trial mode?
I have complete c3 and have been using since photoshop 6.0
cs2 and 3 are fine with vista