POP: SOT won't acknowledge admin rights--Even in admin default

I bought the game Prince of Persia: Sands of Time but
after installing it and trying to run it a Windows error
pops up saying I must have admin rights to run. Then
another error says the game process has been manually
killed. The thing is I'm the only user on the machine
with admin rights--in fact I'm the only user on the
machine period. Here's what I've tried to correct the
problem, just so anybody willing to help can see what I
may have missed while doing so:
--Uninstalled POP:SOT and cleared out the windows\temp
folder as well as all registry references before
reinstalling
--Installed on the builtin administrator's account
--Installed and rebooted before trying to start program
(even though it didn't say it had to be rebooted)
--Created a new admin account and then tested all of the
above
I've made sure that all antivirus software was turned off
during the installations.

All the drivers have been updated and
windows updates have been downloaded. The specs of my
machine are below.

Windows XP
40 GB hard drive
1 GB of ram
GeForce 5600 Graphics card
1.73 GHz processor
DirectX 9.0b

What could be the problem? I'd greatly appreciate any
advice