My computer has been crashing intermittently for unknown reasons. It gives no error message, and 2 out of 3 times, when it restarts, it goes into the 'repairs windows startup" screen. If I bypass this and re-start windows normally, it starts right back up, to randomly crash again. I have tried buying new ram (which is how I ended up with 8gb), and re-installing Windows 7 (Home premium 64bit) with no improvement. I'm at a loss. i have run nortons Diagnostics, which comes back with no errors. (yes, i run Norton's antivirus). Any help would be appreciated.