Windows 7 resolution problem.?

My 19" lcd monitor's max resolution is 1400x900, and that's the one I use every time, in games, computer resolution etc. But last night when I started the computer, the resolution was changed. When I went to "Screen Resolution", 1400x900 wasn't even an option, and some new resolutions appeared, like 1600x1200 (which, ironically, don't even work). Even my in-game resolution for every game is f***ed. I didn't install anything new before this appeared (besides Hamachi). I tried installing new drivers for my video card, didn't work. If it won't work in games, at least tell me how to force a resolution in Windows 7.|||Strange problem... it sounds like it could be a hardware problem, but I don't know does it artefact in games? I've never had a problem like this... weird