CS4 makes use of GPU acceleration. It sounds like ATI broke yet another item in their drivers which is why the program won't start.
I am not sure about which checks CS4 performs when it starts but here is what I would recommend you do:
- Load 9.8 drivers
- Go into CS4, Edit > Preferences > Performance and turn off the "Enable OpenGL Drawing" option
- Load 10.2 drivers and hope that CS4 doesn't do any GPU checks if you have turned off GPU acceleration
See if that helps.
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