Chances are your video card drivers were updated by windows if I had to venture a guess.  Your best bet would be to roll-back the video card driver of your computer.  I don't know your operating system version, nor video card company, and lastly I don't know if your computer is one which uses "OEM" drivers from a company like dell or HP so I cannot be more specific.  But more likely than not the video card drivers were updated to a newer version, which the old game EM4 doesnt like too much.