This was the info I managed to stumble accross:
1. Open RegEdit and browse to HKEY_CURRENT_CONFIG\System\CurrentControlSet\Control\VIDEO\ {the address of your primary video card…it often begins with “23A77BF7″}000\
2. The Default Settings.XResolution data value is the horizontal resolution, and the Default Settings.YResolution data value is the vertical. Double-click the Default Settings.XResolution data entry, select the Decimal radio button, and in the Value Data field, enter your desired horizontal resolution. Then do the same with Default Settings.YResolution to change the vertical resolution.
3. Exit RegEdit and reboot your PC.