Go to Start>Settings>Control Panel>User Accounts
On your account does it say Computer administrator?

Yes

Your version of Windows is XP and not Vista, correct?

Yes its SP2

Record the URL that you are trying to download the driver from (be accurate).
If you are attempting to down through IE7, suggest you check the security settings in IE. Go to Tools> Internet Options>Security
Click on Trusted Sites
Click on Sites
Make sure the Require server veritication does NOT have a check mark in it.
Enter the URL you recorded for the driver.

Close all IE windows. Go back to the Security option and verify that the URL is still there.
If it is, then try downloading the driver again.

I can download it I just can't install it

OK. Click on the Pre-Work in my Signature and follow the directions. If there is a reason for your computer denying access to a driver install, this should tell us.

Good Luck...