Did you turn off UAC? Run as administrator? Turn off Aero/ switch to a differnt theme? Try these things first. Also provide more indfo about your system. there is no magic patch or something, eitehr it installs or it doesn't. It may not be officially supported or endorsed, but some users are using such setups regardless, so there are ways to get it working.
I run AIcs2 on Vista, though it's the only program from the entire suite that refuses to work in Aero mode; old nasty coding, I suppose is the culprit...
I'm no system expert, Mylenium. Here's what I can tell you: yes, I did try the installation as the administrator. No luck. Didn't know to turn off aero or switch to a different theme, so haven't tried that. Don't know what UAC is, so can't (yet) turn it off. Here's the thing: all of the other parts of the suite installed. The setup.ini file for both Illustrator CS2 and InDesign CS2 contains the following:
InDesign installed; Illustrator did not because the OS "was not supported," or words to that effect. Unless "WinNT4" is code for Windows XP, these programs shouldn't have installed on an XP system, yet they did.
System CPU is an AMD Phenom 9600 quad-core. 6 GB RAM. What else would you need to know?