Hardrive acting up...HELP

Hi everyone!
I seemed to have run into a little problem this morning and i was hoping someone could help me out. I recently got a new computer built by a friend of mine, i was on the computer this morning and i wanted to listen to music but there seemed to be no sound card. So i opened the side door to check, and literally like 2 min later my computer restarted...now the first thing that came to my mind is that the cooling was thrown off because there is a fan on that door i took off...but how could it after such a short amount of time...and the fan is so small. Anyways so after it restarted it went to the first loading screen, "the one with the hard drive logo and you have the option of pressing F8 for rebooting." anyways so it froze on that screen. So i restarted my comp. Then after it went to the same first screen and said something about my RAM not sure what else it said...now i didn't touch anything inside...just looked. Then it said if you want to continue loading pressF1 and i did. Then my screen went black. Now everything is just BLACK and i don't know why!!!!! I'm letting that comp cool off maybe the whole "let it sit and it will be fine" thing will work. If you guys know why my screen is just black now and why my comp isn't loading please help me out and give me your input. (From the knowledge i have i know my graphics card is fine unless I'm wrong. Seriously like everything is working fine in the comp it just isn't showing anything.)

please get back and let me know what you all think!

tsar