iLok not required, it's the 002 that authorizes Pro Tools. I'd uninstall anything iLok as a test.
As said above, the 002 and PT 6.4cs9 are qualified for Windows XP SP2:
http://akarchive.digidesign.com/compato/xp/64/002/
Grasping at straws, go to Control Panel>Sound and make your onboard soundcard the default for Windows sounds/audio and disable any instance of the 002 under the Playback and Record tabs.