Im pretty sure I know the answer to the question but I need to make sure, will games like cod4, cnc3 work in vista under DX9, not DX10?

Should work. It requires XP SP2 or Vista and a 6600 Nvidia as the minimum graphics, but it recommends at least a 7800 Nvidia card.

I haven't played it yet. I still am in the Half-Life 2 universe (playing a lot of HL2: Deathmatch), TF2, and Day of Defeat (Source-based ww2 fps).

oh, I know all about the requirements, i was just wondering if it works in vista, well thanks!

As I understand, If you have DX10, you should be able to play anything DX10 or before. As long as Vista will run it. Like one game, Medal of Honor Pacific Assault, I bought used for 10 bucks, could not get it to work on Vista. After an hour and a half of trying and fighting with it, just about to give up, I went to the cd, right clicked and clicked on open, then I found the setup file, and right clicked, and told it run as administrator. Now it works perfect. If you have any problems getting any games installed, try that. I'd tried compatibility, everything. But that did the trick.

I had a problem with joint operations and the problem was more with punkbuster then the game itself. Kept getting kicked and skipping of frames. I found a fix within the JO community. It might take a little longer but any DX9 game runs real smooth in Vista 32/64 bit.