M14X problems with motherboard and Windows 7

Hello, I purchased my M14x back in Nov of last year. I had it for approximately 4 weeks when the motherboard went out, I.E the screen would not turn on but the computer would power up. So, it was sent back for repairs, new motherboard and RAM. I got it back and it was good for about another 3 weeks then bam!, same problem. This time a tech was dispatched to my home and replaced the motherboard and RAM. As he finished his repairs and tried to load the BIOS and other programs, Windows kept locking up, to the point you would have to do a hard restart. He left  my house with the computer still not working properly and I was told to do a Windows reinstall. Flash forward to today, After a fresh install, new and updated drivers and no other programs loaded on the computer except SWTOR, Windows still locks up for no reason at odd times. I can plat SWTOR for hours with no problems, but as soon as I exit, window will lock up, forcing hard restart. I must repeat this process several time before it will function for a short while. I plan on calling them in the morning, but am not hopeful the problem will be solved without me having to ship it back for reapirs a 3rd time! All I want is a computer that works, any help or ideas is appreciated.