Is it possible for you to read the information on that blue screen and write down the error code? What we are looking for in particular is 0x followed by a lot of zeros and ending in a letter, number, or letter and number combinations. Like this (there are other letters than just A; this is for clarity):
0x0000001A
0x0000000A
0x000000EA
0x00000050
0xC000009A
0xC0000135
0xC000021A
* Trust me, there are many combinations. Don't worry about writing all the numbers down because it is the last two or three that are important here.
* Also, many times the blue screen will list a probable cause before this number sequence such as symevent.exe; give us that if you can.
* Does your motherboard give any error code beeps? What is your power supply, i.e., make, model, and wattage?
* If possible move your harddrive to another system that you know is working properly and see if you can access your harddrive and information. We are trying to see if your harddrive is good.