HELP I broke my computer!! Oh Noes!

Yesterday I was installing the DVD burner that my dad gave me for my birthday. And I got it in, and it seemed to be working, (I had started to make a doctor who dvd for Ruth) when I attempted to minimise the application, and click on my computer, and it crashed, and then re-booted. But it failed to restart. It has since failed to restart AT ALL! I turn it on, the Windows XP logo comes up then it goes black, it sounds like it might be booting (there's little grinding and the light blinks) but it doesn't make the "Beep Beep" of the start up noise. Just a black screen. I can turn it on and off with the power switch but that is all.

I am so sad!!! I want my lovely computer to work! I have games and shows and pictures on it!!!

I took the cover off on my dads advice and tried to make sure everything was connected properly but it still won't go! Any advice from my more tech savy friends out there??? PLEASE??? I will get you much beer or dinner or whatever you like!!!!

EDIT: Is thinking it might be a master/slave problem with the drives. Am going to attempt to remove and check. And hopefully that'll work. Thanks for the help!