Hi, I got the same message (Catalyst Control Center incompatible and should be uninstalled prior to proceeding, along with Catalyst Install Manager) during my free upgrade from Vista Home Premium 64-bit on my HP Pavilion notebook, using DVDs from HP and Microsoft supplied by HP. I took the risk of ignoring the message and did NOT try to uninstall Catalyst Control Center before proceeding. The upgrade went fine anyway, though Catalyst Control Center of course no longer worked (would not open upon launch) after upgrade. I continued with the HP software portion of the upgrade which took care of updating Catalyst Control Center and everything works just fine. (Note: I did have to go in to Task Manager because when I launched CCC to test it in between the Windows and HP software upgrades, the CCC process was still active despite it not having opened successfully. You are best off to just ignore it and don't try to launch it until you fully finish the upgrade.)
If you don't have the HP upgrade disk then you are best off using your HP Advisor software after you install Windows 7 to update all the associated drivers
and software; or as others have suggested, go to the ATI site to upgrade your software and drivers for the hardware. In my case everything was safe for the upgrade, regardless. I was very glad I ignored the compatibility issue and did not try to hunt for the uninstaller, which seems to be hard to find for this program. Hope this helps a few people. Don't worry be happy!
By the way, the Windows 7 upgrade went very smoothly though it took a long time. I went to the movies while the upgrade was in progress! It doesn't make a huge difference but I think people need not fear the upgrade. I could still print to my "ancient" Brother MFC-8300 printer that I had managed to get to work under Vista previously by hunting the Vista forums- that was my biggest fear. I don't know if it just used my Vista driver
or if 7 actually has a native driver (Vista did not have a working driver for it). The program seems well equipped with drivers and seems to run things (including booting, opening my desktop, opening programs, and surfing the web) noticeably faster, but we'll see how long that lasts.