Yesterday, it worked fine, haven't changed anything. And today, it shows my desktop 3 times and quits, whenever I launch the game. Doesn't give any errors, just quits.
How do I fix this? Thanks in advance.

P.S. if it helps, my sound doesn't work for some reason, I do not know why, it happened today too.

sound doesn't work... for anything?

It sounds like a windows update or driver update messed up something with how windows accesses the resources in your expansion slots (sound, video), so therefore it has trouble trying to change video modes and play sounds. This is also my theory even if you have sound built into your motherboard, because that still uses the PCI bus. (AGP also uses PCI resources as well if you have an AGP video card)