Make sure it is not trying to bootup to secondary hard drive or removable usb thumb drive. Disconnect all secondary hard drives. Chances are with prior freezes, this is not the problem.
Shutdown computer and check loose hard drive cables.
Boot up to startup recovery and open a cmd prompt and run the following:
chkdsk /f C:
sfc.exe /scannow
The problem is probably due to corrupt and or misconfigured files, hard drive and operating system upgrade issues, or corrupt hard drive sectors...