I own XPS15 L502x. and  got problem in booting windows 7. It just shows starting Windows for hours and hours nothing else...Also tries to reinstall Win. 7 using OS cd which came along but even that could not load...freezes after some time..... tried system test using F2 and shows error 0146. I even tried load optimization default after reading from another forum...so any suggestion ?? is it  HDD failure ??  It is still under warranty...so should i go replace it or is there any home based solution ???