I just upgraded my graphics card for the first time from a hd2400pro to a hd4850. for some reason however when I try to load cod4 multiplayer, it crashes now. itll say that it has detected new hardware and asks me if i want to run at optimal settings and whether i click yes or no, it crashes. my guess was that it is a driver issue. here is what i tried. i uninstalled my drivers for previous card through "device manager--display adapters" and cleaned the "ati-display" drivers using "driver sweeper". then i restarted the computer and installed the latest 4800 series drivers from ati.com. after doing the mandatory restart, i try to open cod4 but it still wont let me. Can someone help? Also to add, i reinstalled cod4 as well just in case but the problem still exists. next time ill try deleting the activision folder from program files and reinstall just to see if thatll help.