[Closed] Computer help - before I throw it out the window

I've just had a new computer desk made. I don't think it's got enough ventilation as my computer got a bit warm :cry:. I shut it down when i noticed it was slowing down and that the fans were going flat out.

I've managed to get it going in Safe mode with Networking after letting it cool for 30 minutes or so.

It still won't boot up in normal mode. The hard drive light remains on but the computer monitor goes off like it is in standby mode.

So I can't keep running it in safe mode but will do so until I've got everything copied onto a portable hard drive.

Any suggestions on what it might be? Am I likely to have cooked it to death? Or are there other things I should be checking? Might a clean install of windows help?

Any suggestions on how to keep it (or its replacement cool if I lose). Its a desktop, for now I can leave the cupboard open and in a few days drill more ventelation holes in the back. I'm reluctant to install a water cooling system or anything else expensive but am looking for cheap/easy solution.

Thanks,