hey guys. i busted my laptop, so unbeleivable. i had a external fan that stay under the laptop, somehow that fan didn't work at all. so i thought i was wrong with the wire and cut the wire to fix the problem. but i couldn't figure out which end was not working. the two end of the wire was connected to the fan and another to the laptop at USB port.  after i cut the wire in half, i try to connect the wire that was connected to the fan to the laptop charger and i didn't work, and again to figure out i connected the wire to that same charger to the wire that was connected to the USB , and LAPTOP got BOOM>>>>>>>>

i thought there was some kind of shot in wire or mother board is gone or hard drive is gone. Do any one have any IDEA what was the problem and i have tried to connect that harddrive to the another computer, that  HD doesn't work. i am trying to get  some important File that i was supposed to submit at college,but HD is gone. Do any one knows how to get those file from that Hard Drive? some ppl says that anything can be recoverable...

I really appreicate for the kind suggestion, i need some computer master

thanks

Shit happens, always backup.
Btw try connecting the HDD to another computer If it rotates you might be able tosalvage some files from it. There is a free software called PhotoRec that brings back the deleted and corrupt files. Give it a shot. 
http://www.cgsecurity.org/wiki/PhotoRec

USB port output just mere 5 volts which is insignificant to cause any major damage to your laptop cooler. First off, you should not have cut the wire without knowing what was wrong. It was mechanical fault which is why your cooler fan didn't work. You could have bought new one at around $9.99
I doubt if the usb wire caused any major damage to your laptop. If your laptop's built-in fan was already dead and was solely depending on external laptop coolers fan, most probably you let it fry itself, like CPU, motherboard and everything.. and I believe it's HP laptop. Certain HP laptops are defunct with their BGA chipset design, upon heating, it melts pretty fast rendering your laptop useless.
It takes a long route to damage your harddrive even if your motherboard is fried up,.. And, the way you described your way of doing things, I'm pretty much sure you lack a knowledge on how to retrieve data off your harddrive. Make sure if it's 2.5 inch SATA or IDE, find a USB connector on ebay, connect it and retrieve it from the working computer.