Windows 7: Windows will not load and crashes on startup repair

Hello i would appreciate all the help i can get. I have an acer aspire 5742 laptop. I was running windows 7. I do not have a disc as it was already loaded onto laptop that was a gift. Machine was running ok, it would overheat from time to time as i think the battery was on its way out, anyway thats not the problem. 2 days ago it switched itself off, when i tried to reboot i got a screen saying windows failed to start with options to -launch startup repair or - start windows normally.
when i choose start startup repair it says in grey at bottom of screen loading windows files then it goes to a black screen and freezes.
If i choose start windows normally it says starting windows and logo appears, then it just crashes. Please help me.

What is on the crash screen?
Boot into advanced boot options Advanced Boot Options
and select :
Prevents Windows 7 from automatically restarting if an error causes Windows 7 to fail. Choose this option only if Windows 7 is stuck in a loop where Windows 7 fails, attempts to restart, and fails again repeatedly.

Now crash information stays on your screen.

Overheating is not a good thing! Can be caused by dust or thermal paste on cpu not fitted nicely anymore. Don't put laptop on a blanket so ventilation is fine. It isn't too hot now?

windows recovery environment should boot in case of problems (normally). Unless:

• faulty memory
• faulty harddisk
• faulty mainboard
• virus
• etc

first test your harddisk. Then memory. Do you have a Windows 7 system repair disc (64 bits)? Do you have a Windows 7 install dvd (64bits)? You can create a system repair disc on another Windows 7 machine.