Final Update:

After multiple experiments, the technician finally concluded that the problem was my mother board. After telling SONY about the problem, they agreed to ship me a new one. Two days later, the technician brought my laptop back with a brand new motherboard and it is now working flawlessly. (With all my files still on it I might add!) :-D

Thanks everybody for your help and believe me, I will be backing my files ALOT more often. (I'm doing it right now.) :-)

-Peter