Need some help with my computer ASAP n

[Hayden1]

Long story short, I've got exams on right now (english tomorrow) and some important files are on my computer which decided to stop working luckily just after I saved a half completed essay.

Hopefully someone here can help...
I'm running windows 7
Copied and pasted some text into a word doc and word went unresponsive so I crapped myself but then it responded but it was slow. So I saved it and restarted the pc. It got stuck at the shutting down thing for a couple of mins so I just held down the power button til it shut off. Then I turned it on but it just went black after the windows screen. Restarted and it said that windows failed to start and gave me the choice to start it normally or do a system recovery. I tried normally again but no good so I did the system recovery thing and it tried to repair it but didn't work (all tests completed successfully). So now I'm at a screen with the options to:
Startup repair (done as above)
System restore (need files on it I did today)
System image recovery (whats that + tried it and I don't have any images)
Windows repair diagnostic ?
Command prompt ?

I'm not amazing with computers but if you give me detailed instructions then I should have no problems

Sorry for any grammar mistakes as I'm writing from a phone which has taken ages and is giving me a headache

Thanks heaps for any help in advance

Edit if u need my specs I will put them up soon as I'm trying to find them thanks