What version of Windows? The 7B error message suggests the SATA Operation (SATA Mode) setting got changed in BIOS Setup or possibly the hard drive may be toast. Reboot and press F2 before Windows starts to load to open BIOS Setup. Look for the SATA Operation or SATA Mode option (different models name it differently).  I don't see BIOS screen options in the online manual but options for this setting may be: RAID Autodetect/ATA, AHCI or RAID. Post back and tell us exactly what options are available and how it's set now. While you're in BIOS setup, also look for the Boot Sequence option and make sure the internal hard drive is listed as first on the list. If it's not first, move it to first, save the change, and exit setup. See if it boots now. If you reinstall Windows using a Dell Windows Reinstallation disk, it shouldn't ask you for the product key. It should install automatically by itself. HOWEVER, you will need to have product keys for any other apps you want on this system, eg Microsoft Office, so be sure you have those product keys and installation disks before you wipe the hard drive.
I'm trying to recover a friend's laptop (Dell Inspiron N5010) that was infected with a ransom malware (ICE Cyber Crime Center - Backdoor.Win32.ZAccess.erds). I've used the Kapersky Rescue Disk to remove the ransom virus but now Windows will not load and I suspect the MBR has been affected.  On bootup, the Dell logo appears and the Window loading appears briefly, but then you get the "blue screen of death" flashes and the cycle repeats.   The bsod error is:  A PROBLEM HAS BEEN DETECTED AND WINDOWS HAS BEEN SHUT DOWN TO PREVENT DAMAGE  TO YOUR COMPUTER    IF THIS THE FIRST TIME YOU' VE SEEN THIS STOP ERROR SCREE,  RESTART YOUR COMPUTER. IF THIS SCREEN APPEARS AGAIN, FOLLOW  THESE STEPS:    CHECK FOR VIRUSES ON OUR COMPUTER. REMOVE ANY NEWLY INSTALLED  HARD DRIVES OR HARD DRIVE CONTROLLERS. CHECK HARD DRIVE  TO MAKE SURE IT IS PROPERLY CONFIGURED AND TERMINATED.  RUN CHKDISK /F TO CHECK FOR HARD DRIVE CORRUPTION, AND THEN RESTART YOUR COMPUTER.    TECHNICAL INFORMATION  *** STOP: 0X0000007B (0XF78D2524, 0XC0000034, 0X00000000, 0X00000000)   The F2 and F12 keys work , but the F8 key will not open the "Advanced Boot Options", so I can't get to the "Dell DataSafe Restore and Emergency Backup" or any other advanced option.  System Restore will not work either.  I ran chkdsk and sfc on the hard drive (via the Kapersky Rescue disk) and neither fixed the problem.  Then I copied his data off the hard drive.  I'd like to restore the laptop back to the factory settings (assuming that would be better than reinstalling Windows since the Dell drivers would be included already?).   There is a folder on the hard drive called "Emergency" and contains a Backup*.exe file and multiple Backup*.dsb files.  Given this scenario, is there a way to restore to the original factory settings?  Or am I forced to reinstall Windows from scratch?
How to restore original factory settings when Windows won't load?