To prevent blue screen of death problem again, the fastest and easiest 'risk free' methods are.
1.Click Start, and choose Control Panel, later enter into Hardware and Sound.
2.A new window open, under Devices and Printers select Device Manger.
3.You can see a list of devices. The devices in the list turn out they connects well with the pc, if not, it says the devices don't connect to your computer.
1.Click Computer on your desktable and right click Disk C to select Properties.
2.Click Disk Cleanup, you'll see a window just as right, this process need some minutes.
3.Under Disk Cleanup there are Files to delete, tick the files you don't need to free pc space, finally click OK.