Search google on how disable automatic restart. It might be reveiving error's and rebooting. Once complete, do it again and if it bluescreens, post the error. If it keeps doing the same thing then we know its something different.
A+, Network + , HP Certified Tech and MCP
Specs: AMD Phenom II X6 1095T, Asus M477TD, 8GB GSkill Ripjaws DDR3 1600 7-8-7-24 1T, 128GB Crucial M4 SSD, ATi HD4650, W7, 27" HL272 Monitor