My computer is stuck at startup?

I was playing garrys mod and my computer froze. My computer meets the system requirements. It had been frozen for about 10 minutes so i turned off the power strip. When i tried to turn it on it came up with a screen with different ways to start the computer like "safe mode with command prompt","safe mode","safe mode with networking","last known good settings","start windows normally". I have a gateway computer running windows xp. The only option i know of to fix it is to restore to to factory settings but i dont want to lose my documents. Please help!!!