I have a Gateway PC AMD 64 x2 with Vista home. When I bought COD4 I kept getting the iw3mp.exe error and by way of the forums found out that it was my Realtek Hi Def sound drivers. Once I uninstalled these drivers everything worked fine but then last week I get this ATI 3850 with built in HD audio and now not only does the multi player not work but the single player has stopped as well. I have tried reinstalling the game and I deleted/disabled everything known to man but as soon as I double click the COD 4 icons these errors pop up. Oh by the way my nvidia 7600 GS 512mb worked fine before I installed the 3850.[/b]