I have a g75vw Asus laptop which for the most part has worked fine. Late June the computer simply wouldn't boot into windows giving the error 0xc000021a next to the " " icon. This computer was originally using windows 7 but I upgraded soon after windows 8 was released in October. For about a week before the crashing, I had been using a ubuntu 12.04 live boot jump drive for learning python. It was after a linux boot that the computer crashed but I do not think the events are related. I had also installed connectify.me, a program that turns a laptops wi-fi adapter into a router which worked well for about a week before the crash. I have gone through all of the generic hoops including safe mode(s) system recovery using a usb flash drive, refresh, and the existent yet worthless self diagnosing tool. Microsoft was unable to help without a 100 dollar fee.