With Vista, it's highly recommended that you have at least 2 GB (2048 MB) of RAM. In the chance that you can get yourself upgraded to 64-bit Vista, go with at least 4 GB.I have had no issues, compatibility, performance, or otherwise with Vista. I might get a rare crash, but it's no different than what I experienced with XP; XP was no more stable than Vista has been, though this will most definitely vary from machine to machine.Not too sure of your video card, I stopped using ATI cards after the Radeon 9000 AGP. However, after doing some brief research, it looks as though that card should work, though you may have to cut the graphics/effects settings back for tolerable frame rate performance.Your CPU shouldn't be an issue.The only other thing I can think that can tend to make a bit of a performance difference is your RAM. You say you have 1 GB, but what speed is it? Is it DDR or DDR2? PC3200, PC5400, PC6400, etc?Also, I'm pretty sure there is a thread dedicated to system requirements around here somewhere; you might be able to find more thorough answers to your questions/concerns.