INACCESSIBLE BOOT DEVICE

Hi Khang. I'm Greg, 10 years awarded Windows MVP, specializing in Installation, Performance, Troubleshooting and Activation, here to help you.

Were you using CCleaner? I would no longer use it since it was sold to Avast bloatware and lost it's genius developer. Use built-in Disk Cleanup to be safest. And any registry cleaner is death to Windows.

Try these fixes for Inaccessible Boot Device:
https://docs.microsoft.com/en-us/windows-hardwa...
http://pcsupport.about.com/od/findbyerrormessag...
https://www.thewindowsclub.com/inaccessible-boo... (Avoid ad links which intrude into editorial copy, especially avoid Restoro and Reimage ads)
http://pcsupport.about.com/od/findbyerrormessag...

If nothing there helps, Use whichever method works in this link to get into Repair Mode so you can do the necessary repairs or do a Reset: https://www.tenforums.com/tutorials/2294-advanc...

Easiest is to force shutdown by holding in the power button. Do this twice. The third time you power on it should start into Repair Mode. Once in the Repair Mode try the numbered steps below.

It may be necessary to create bootable media on another PC to access Advanced Startup Options to try repairs, a Reset or do the Clean install. The bootable media has it's own set of files so that repairs or Reset might work better, doesn't require a password, and you'll have it to if necessary do the vastly superior Clean Install.

To create Windows 10 Installation Media on another PC install Media Creation Tool and follow the directions here: http://windows.microsoft.com/en-US/windows-10/m.... Uncheck the box for Recommended Settings to choose the exact version and bit rate for the target PC only.

Insert media, boot it by powering up PC while pressing the BIOS Boot Menu Key given here: https://www.sysnative.com/forums/hardware-tutor...

If the media won't boot you may need to enter BIOS/UEFI Setup (pressing key given in chart in link above) to turn off Fast Boot or Fast Startup first.

Choose the boot device as a UEFI device if offered, on second screen choose Repair Your Computer, then Advanced Troubleshoot Options, then:

1) Try a System Restore,

2) If that fails try Uninstall Updates as far back as necessary to see if this was caused by an Update,

3) Open the Command Prompt to:

a) run System File Checker: https://www.wintips.org/how-to-run-sfc-offline-...

b) run a full Disk Check: https://www.windowsdigitals.com/how-to-run-chkd...

c) trigger Safe Mode with Networking (for internet) or Safe Mode following https://www.intowindows.com/boot-windows-10-in-... to roll back Updates & Drivers in Windows Update History, update your drivers from the PC/Motherboard manufacturer's website and diagnose further:
https://www.pcmag.com/news/354269/how-to-use-sa...

d) Enable the built-in hidden Admin to sign in to create a new Admin account to replace or repair yours:
https://www.tenforums.com/tutorials/2969-enable... (Option Five)
http://www.howtogeek.com/226540/how-to-create-a...
You can also try to repair the old account from the new one by running a Repair Install: https://www.tomshardware.com/how-to/fix-windows...

d) From the Command Prompt try to create a new Local Admin Account to replace your account: https://www.isumsoft.com/windows-10/3-ways-to-c..., sign in to test it, move files over, when ready delete the old account and if desired change the new one to your MS Account.

4) If those fail then go back to Troubleshoot Options to do a Reset.

5) If that fails choose Install Now, then Custom Install, then at the drive selection screen delete all partitions down to Unallocated Space to get it cleanest, click Next to let it create needed partitions and start install - this makes it foolproof. Everything needed to get the best possible Clean Install is here: http://answers.microsoft.com/en-us/windows/wiki.... It is a better install than any amount of money can buy and a great learning experience that will make you the master of your PC because you will learn what works best and how to apply it with your own hands.

6) If you have files that aren't backed up you can use the same bootable media to try to rescue your files using these methods: http://answers.microsoft.com/en-us/windows/wiki...

Your files should be backed up at all times if you value them at all. In the Clean Install tutorial in Step 5 I give the best methods to back up.

I hope this helps. Feel free to ask back any questions and let us know how it goes. I will keep working with you until it's resolved.

________________________________________________________
Standard Disclaimer: There are links to non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the sites that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the sites before you decide to download and install it.

Hi Mr. Greg,

Thanks for your response.

I have tried 3), everything runs fine, I have created new account but I don't know how to login to it.

Also, I just discovered that I have 2 windows 10 volumes, and that their data can be accessed interchangably.

So, can I install my new windows 10 to another volume?

Regards,

PS 2: I don't know how to create new windows 10 volumes. It just popped up after upgrading my PC about 5 months ago.

Hi Khang -

When you say everything runs fine, are you referring to the Commands in Step 3 or is WIndows now working? If so post a screenshot of Disk Management: http://answers.microsoft.com/en-us/windows/foru...

If not try running Startup Repair and report back results:
https://www.tenforums.com/tutorials/2294-advanc...

How did you discover you have two Windows volumes? Is it possible you have a large data partition in addition to Windows 10? Can you copy the data out of it using one of the rescue methods in this link, so you can install Windows 10 to it?
http://answers.microsoft.com/en-us/windows/wiki...


From Command Prompt, run:

DIskpart
List DIsk
Select Disk # (replacing # with Windows 10 disk number)
List Volume

Please post back a camera snap, or write out the output reported.


I'm assuming you create the new account from the Command Prompt?

If so and you didn't include a password command, then you'd restart PC to see if it goes to the Sign-in Screen, choose the account, leave the password blank, then press Enter.

This may not be possible if Windows is still inaccessible.

Please answer or clarify all points above. I am standing by here.

Hello Mr.Greg,

Thank you for your reply.

When I say everything runs fine, I mean commands in the cmd runs fine but Windows still can't boot.

This is the output of Startup Repair:

This is the output of Diskpart:

This is the output of select disk and list volume:

And Windows still isn't accessible, so I can't sign in to my newly created Admin account

Where is List Volume output, after Select Disk 0 which is apparently the Windows disk? Half the steps were not done.

Please continue with the steps I gave which lead up to if necessary doing a Reset or the superior Clean Install.

I also show you how to rescue your files if they are not properly backed up.

Everything else possible to get WIndows 10 to start is here: http://answers.microsoft.com/en-us/windows/wiki...

Hi Mr.Greg,

So, if I reset my PC and choose to keep my files, which folders will be reinstalled and which folders remain the same?

Regards,

First, your files must be backed up at all times because any reinstall can fail, or a hard drive can die at any time without notice. So if you value them at all your files should be backed up. I can give you easy free steps to do this.

The files saved after a Reset where you choose to save files are your User folders in C:\Users\Your User Name.

Hello Mr.Greg,

Thank you for your advices.

I've got my Windows 10 to boot up again.

Regards,

I am so glad to hear this, Khang!

As promised here are some free and easy backup steps so your valuable files are not at risk:

The safest and most reliable backup method is to sort your files into their User Folders (Documents, Desktop, Pictures, Downloads, etc) and periodically drag or copy them to external or another hard drive. See tips for copying large groups of files here: http://www.pcworld.com/article/2086566/the-many...

Then have one other Cloud backup so your files are safe from ransomware, fire and theft and easily accessible via the internet just like email. Some suggestions to help ease into this habit:

You can drag or copy 5gb for free into OneDrive app to store in the cloud where they are safe from fire and theft. You can also choose to sync the Desktop, Pictures and Documents folders (only) in OneDrive app Settings > Backup for real time backup. More here:
https://www.tenforums.com/tutorials/116029-turn...

If you install Google Drive, you can use their new Backup to choose ANY User folders (Documents, Pictures, etc.) to sync up to 15g for free to their cloud in real time. You can also drag/copy selected files into Drive folder. More here:
https://www.cnet.com/how-to/get-started-with-go...

Besides your files you should back up a System Image to use in place of reinstall in 20 minutes. The best free alternative is Macrium:
http://www.howtogeek.com/howto/7363/macrium-ref...

There is an easy way to mount the System Image to extract files if needed. Some prefer to move their User folders off of C to make the image smaller and so they stay current if you need to re-image C. Here's how to move User folders to a data partition you create:
https://www.windowscentral.com/how-move-default...

This way if Windows ever becomes irreparable you can restore C in 20 minutes from recovery media, and your files will be current and safe in their own separate partition. If they are left on C they will be dated from when the image was taken.

I hope this helps. Feel free to ask back any questions.

________________________________________________________

Standard Disclaimer: There are links to non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the sites that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the sites before you decide to download and install it.