Hi, a while ago I scraped together enough money to buy a cheap PC, this one: http://www.newegg.com/Product/Product.aspx?Item=N82E16883227442. But, I wanted a gaming PC, so later on I got an Nvidia GTX 660 3gb, and I upgraded the power supply to a 600 watt Corsair PSU. this build had been running fine until about 2 weeks ago when the restarts began, It restarts randomly even when I'm not doing anything, and about 3 times now has restarted while I'm booting my computer up at the beginning of the day, any answers would be helpful, thank you.