It crashes during the boot with a BSOD and error code is 0x0000007E. I've also tried Safe mode - it gets stuck there on a file AVGIDSHS.sys which is in the system/drivers folder. So I'm guessing this is the culprit.
I can access the hard drive via another computer so would it make sense to delete that AVG file and see if it gets better?
I have already run chkdsk /r on it couple of times without any success.