If it's not allowing you to even load the setup launcher where resolution, aa/af and distance settings can be chosen then it sounds less of a driver and gpu conflict and more like a general executable compatibility issue.
If you give it a try running in each of the compatibility modes 2000, xp, win 7 and see if it will let you launch it. Just to make sure it's this file to try launching: \Buka\Pathologic\bin\Final\Config.exe
See how that goes with compatibility modes.
If you can then get into the game then problem solved
![Улыбается :)](./images/smilies/kolobok_smile.gif)
If there are more issues in game from then on then it might be worth trying older drivers. This might be what you're looking for in that case:
http://www.oldapps.com/ati.php
Not sure which Ati/Amd drivers work best as I use an older Nvidia card to play Pathologic on an XP machine.
Best of luck though and if I can help just give me a shout
![Улыбается :)](./images/smilies/kolobok_smile.gif)