As we know, WDDM driver doesn't support INT 10 communicatations with VBIOS because of the unstability. So when WDDM driver is enabled, cmd prompt cannot be switched to full screen mode by pressing ALT+Enter. reference: http://www.microsoft.com/whdc/system/platform/firmware/wddm_bios.mspx But after you disable and re-enable your display driver in device manager, you can find that the command prompt CAN be switched to full screen mode. The problem is after you switch it back, the resolution is not the previous one, it still keeps the VGA mode. So my question is, is this known issue to windows 7? Will it be fixed in Windows 8? I may already know the root cause. If it is an known issue and you have a waiver, please advise a link.