Run Dell Diagnostics from BIOS/Setup:Immediately after pressing the power button to turn on the laptop (or after clicking the Reboot command), press and hold (or repeatedly press) F12 to enter the One Time Boot Menu, select Diagnostics and press Enter. The Dell Diagnostics will test major hardware components. Choose to run the extended tests. It would also be worthwhile to run chkdsk /r on each partition. Also check S.M.A.R.T. information with something like CrystalDiskInfo. If any of the tests show uncorrectable errors, stop using that computer. Remove the drive and use an external USB drive interface or enclosure, or a spare drive bay in another computer, to backup your data before full drive failure.
I have status 79 on my hard drive, but I can boot to my system, and do pretty much anything. I have BIOS revision A05, planning to update soon though.
Diagnostics error - Error 79 on hard drive but my hard drive works fine?