Inaccessible Boot Device

I fired up my PC yesterday morning and was welcomed by the dreaded BSOD. It told me that it had run into a problem caused by an inaccessible boot device. There are numerous help sites on the web that explain how to deal with this issue. I tried every one of them bar one and none of them got me up and running again. The only one I haven't tried is the hard reset option. Although I have backups of most of my files, I didn't want to lose what's on my hard drive unless it's absolutely necessary. Reinstalling all the applications is going to be a big enough PITA. I'd be interested to learn whether anyone else hit the same brick wall and wound up wiping their hard drive because nothing else worked.
Having spent most of yesterday trying to resolve this problem and getting nowhere, I am wrestling with the idea of ditching Windows altogether and switching to a Mac. Anyone want to give me an argument?
BTW I typed "Inaccessible Boot Device" into the search box on the BSOD forum and got zero results. Really?
I

CMOS Checksum Error before? Or connecting HDD to different controller/port?
Try to change SATA mode in BIOS, preferred is AHCI. Revert HDD connection to previous state.

What options does the bios boot menu offer?
Is your ssd/hard drive one of them?
If you do not have a bootable usb/disk available,then access to another computer is required to make one.Read and understand the method of use.

It can only be a software issue or it may be that your drive is dying.
Fist thing to do is to make a rescue USB drive
Boot from the rescue USB drive and run a check disk (chkdsk x: /f) Replace x with drive letter you see under explorer

"BTW I typed "Inaccessible Boot Device" into the search box on the BSOD forum and got zero results. Really?"

There are threads in the BSOD forum dealing with "Inaccessible Boot Device"

The INACCESSIBLE_BOOT_DEVICE bug check has a value of 0x0000007B. This bug check indicates that the Microsoft Windows operating system has lost access to the system partition during startup.

If the PC suddenly loses access to the system partition during startup, then the “0x0000007b” error screen is displayed and the boot process is halted.

• Make sure Windows installed hard drive connected correctly.
• Make sure Windows installed hard drive first boot device from within BIOS Setup Utility.

Enable AHCI Mode in the BIOS

Some users have reported that enabling AHCI mode in your system BIOS instantly solves the inaccessible boot drive error.

The BIOS menu can vary considerably between manufacturers, so there's not a one-size-fits-all way of explaining the process.

However, in general terms, you'll need to enter the BIOS during boot (typically by press Escape, Delete, or one of the Function keys), head to the Advanced Options menu, find Set AHCI Mode, and change the value to Enabled.



Repair Boot Sector

Boot your computer with Windows Installation DVD and from Windows Recovery Environment start the Command Prompt.

Type below commands one at a time at the Command Prompt and press Enter key for each command you have typed.

Following commands will repair Master Boot Record (MBR), Boot Sector and BCD Store.

Code:

Bootrec /FixMbr

Bootrec  /FixBoot

Bootrec  /RebuildBcd

Check The Hard Disk With CHKDSK Utility

Boot your computer with Windows Installation DVD and from Windows Recovery Environment start the Command Prompt.

Type below command at the Command Prompt and press Enter key.

Following command will fixes errors on the disk and locates bad sectors and recovers readable information.

Code:

Chkdsk C: /r

Replace partition drive letter C: with Windows installed partition drive letter. When computer boots into Windows Recovery Environment (WinRE) environment the drive letter assign to Windows partition may not be C: drive letter because Windows 7, 8 , 8.1 and 10 creates a separate system partition when it's installed from scratch. The system partition contains boot files WinRE assigns the system partition the C: drive letter and the Windows installed partition will be assign any other drive letter usually D: drive letter is assign to Windows installed partition. The Bcdedit /enum | find "osdevice" command can be use to find out the drive letter of the Windows installed partition the output of the Bcdedit command is similar to this osdevice partition=D:. The drive letter after partition= is the drive letter of the Windows partition.





Repair Corrupted Windows System Files With the SFC Utility

Boot your computer with Windows Installation DVD and from Windows Recovery Environment start the Command Prompt.

Type below command at the Command Prompt and press Enter key.

The following command scans integrity of all protected Windows system files and repairs files with problems when possible.

Code:

Sfc  /Scannow   /OFFBOOTDIR=C:\   /OFFWINDIR=C:\Windows

Replace the partition drive letter C: with Windows installed partition drive letter.

Thanks for all the advice concerning this issue. In response to the various options highlighted by Free Booter, I can report as follows:
AHCI was already enabled in BIOS.
Bootrec /FixMbr "Operation completed successfully."
Bootrec /FixBoot "Access denied."
Bootrec /RebuildBcd "Successfully scanned Windows installations. Total identified Windows installation: 0 The operation completed successfully."

I had already run chkdsk /r /f and it scanned for about four hours and reported that it found no problems.

The SFC utility returned the following report:
"Windows Resource Protection found corrupt files but was unable to fix some of them. For online repairs, details are included in the CBS log file located at windir\Logs\CBS\CBS.log. For example C:\Windows\Logs\CBS\CBS.log. For offline repairs, details are included in the log file provided by the /OFFLOGFILE flag."

I can feel the Mac coming on!

You will have to use Diskpart command to find out the System Reserved partition drive letter.
The output of the below commands may display the name of the System Reserved partition as only System or ESP.

Type diskpart and press Enter.
Type list volume and press Enter.
Under the label row, find the label System Reserved and note its corresponding Volume number.
Now type select Volume=N and press Enter, where N is the Volume number you noted earlier.
Now type assign letter=w and press Enter.
Type exit and press Enter.
Type bcdboot C:\Windows /s w: /f ALL and press Enter.


Please replace partition letter C: with Windows installed partition letter. When computer boots into Windows Recovery Environment (WinRE) environment the drive letter assign to Windows partition may not be C: drive letter because Windows 7, 8 , 8.1 and 10 creates a separate system partition when it's installed from scratch. The system partition contains boot files WinRE assigns the system partition the C: drive letter and the Windows installed partition will be assign any other drive letter usually D: drive letter is assign to Windows installed partition. The Bcdedit /enum | find "osdevice" command can be use to find out the drive letter of the Windows installed partition the output of the Bcdedit command is similar to this osdevice partition=D:. The drive letter after partition= is the drive letter of the Windows partition.





The Install.wim is the source of where these corrupted or missing files located.
The Windows Imaging Format (WIM) is a file-based disk image format. It was developed by Microsoft to help deploy Windows Vista and subsequent versions of Windows operating system family.
The following command can be executed to extract corrupted or missing Windows Component Store files.

Code:

DISM  /Online  /Cleanup-Image   /RestoreHealth     /Source:WIM:X:\Sources\Install.wim:1    /LimitAccess

Replace the X:\Sources folder path with a folder path where Install.wim image file is stored.
The /LimitAcess parameter tells DISM utility to not to use Windows Update service to retrieve corrupted or missing files.
The /Index parameter tells DISM utility to retrieve the corrupted or missing files from which edition of Windows OS. The Install.wim file can contain more than one edition of the Windows OS. You can execute following command to found out index number of your Windows OS edition that you want to repair.

Code:

Dism  /Get-WimInfo  /Wimfile:"L:\sources\install.wim"

Replace the L:\sources with directory path where Install.wim stored. As you can see there is two editions of Windows 10 and all have index number.

After you have executed Dism command correctly execute SFC command again.

Free Booter - Thank you for all this information but I fear it is to no avail. I got as far as successfully creating boot files but then when I tried the DISM online cleanup I returned an error code 50 saying DISM does not support servicing Windows PE with the /Online option.
I tried skipping this and going onto the "Get-WimInfo code but wasn't sure where to find the drive letter for the sources. I tried the Windows letter D but it was obviously wrong as the system could not find the specified path.
I'm probably a bit out of my depth and don't want to waste any more of your time but I'm really grateful for your efforts.

Consider these options:

a) testing the drive
b) performing a custom install (saves files)