I am using an Intel D845GVSR motherboard, P4 2.4GHz with 16'' Samsung LCD monitor and the resolution is being set to 1280x768. But whenever I try to play any multimedia file the resolution gets automatically low to 1024X768, initially the screen goes black out and then automatically it is restored to 8-bit color with resolution 600x480 and I cannot modify the desktop resolution after that unless the PC is restarted what is the reason behind this problem.