[SOLVED] W10 Unmountable Boot Volume

[utbas1953]

Hello All, my W10 desktop computer has glitched with the 'unmountable boot volume' error and I have been Googling to find the info on how to resolve the issue. I have a usb stick ready and have downloaded the MS Media Creation Tool onto this W10 laptop I am currently using. I also printed out the instructions of the procedure. I have read of another set of instructions that differ from those I printed. I ran the tool as administrator but because I did not see the accept/deny function or the decision to select if I wanted the result to be used on another PC I stopped the immediate action of the apparent setting up of installing windows. Never having this boot error in the past I am loathe to progress until I know clearly every absolute step to correctly take. Can anyone please give me with this. Thanks. 

[Boggin]

When you click on Download tool now and download the MCT https://www.microsoft.com/en-gb/software-download/windows10  you will eventually get to the first pic I've attached.

You check the lower button to create either an USB or DVD - Next and Next again and then you will see the second pic I've attached.

For me the USB option is default checked - if it isn't for you, then click on it - insert your USB - Next and wait for it to do it's thing where it will download the ISO and create the bootable USB - I normally Ethernet connect for large downloads to get the max bandwidth.

When that's done you will need to boot up with it - you may have to change the boot order on your machine to check the USB drive first.

Sometimes you need to have the USB inserted so it can recognize it and give you that option - machines differ.

Navigate to the Install screen and click on Repair your computer which will give you the advanced boot options.

Click on Troubleshoot - Advanced options and select the Command Prompt.

Enter bcdedit |find "osdevice" and using that partition letter instead of the x I have exampled, enter chkdsk x: /f and see what that reports.

For clarity, that is a Pipe symbol before find and is the uppercase of \

If it reports any KBs in bad sectors then repeat the chkdsk cmd using /r instead of /f

There's also the Startup Repair option which I have little faith in but you can give it a try if you want.

At the cmd prompt there are also some bootrec cmds you could try.

bootrec /fixmbr

bootrec /fixboot (I usually get an error returned for this one)

bootrec /rebuildbcd

That will search for volumes and will return 0 when you only have the one volume installed.

If you still have Windows.old on your machine following the recent updates then it will return 1 and do you want to include that - type n and press enter.

There is another cmd you can try which is for an offboot sfc /scannow which is for a system file check.

Again using your partition letter instead of the X I have exampled, enter -

sfc /scannow /offbootdir=X:\ /offwindir=X:\Windows

Note the space before each /

It will take a while to run but will give its report at the end.

When done, enter exit to close the cmd window, remove the USB then use the back arrows to get to either continue to boot or to shutdown.

Sometimes a simple power shutdown and reboot can resolve problems like these, but I assume you have already tried that.

[utbas1953]

Hello Boggin, Thanks for your info. When I select run as administrator on the downloaded file what does the process say before it gets to choice.1.
I thought my initial attempt to run it looked as if it was going to set up an install to replace the laptop w10 OS. that is why I stopped it going any further.  The desktop built in W10 function of repair etc. failed as did a restore point using the advanced function of the panel that comes up after powering up computer twice and on the third power up auto repair etc. fails. When the USB stick is inserted in the desktop I assume I would have to set the bios to read the USB stick as the first bootable item or will it be automatically selected as the c drive being at fault will not boot up. Thanks.

[Boggin]

You would only get a download file if you selected the ISO option to create a bootable DVD.

My first pic shows that you have to select the Create installation media and the second pic shows it as for creating a bootable USB.

The procedure does everything for you without having to right click on any downloaded file.

If your machine is up to date with the latest update, using the Update now button on the main URL page would fail with the message that you already have the latest version.

I have all of my machines check the DVD and USB drives before the SSD/HDD having changed that in the BIOS.

However, with the machine switched off, insert the USB and tap F12 as you switch on which will give you a one off boot order change.

Select the USB and press enter where it will boot from the USB.

It could be a different key for you but when you first switch on you will see press, could be F2 for Setup which is the BIOS and another key for the one off boot order change.

As far as I know, it's usually F12 but I don't know every machine.

[utbas1953]

My PC bios enter is f11. I have a MSI motherboard in a Cyberpower PC. Will I lose any data using the USB drive method. I do have a factory reset disc that came with the computer but that wipes out all personal data and perhaps that would also fail because of the unmountable boot error. On the last day of April I clicked Windows Update and downloaded the 1803 update to take over from 1709. It reached installing 88% and then I got a
 PC error and it reverted back to 1709. The computer carried on working ok for a few days and then I got a black screen error so when the auto repair action failed and the panel came up with the advanced functions choice I did a reset to keep my user personal files. I keep all my bought and free programs data backed up on an external drive so began initially to reinstall a small number of bought programs.  A few days after I was informed that 1803 was available in Windows update and that installed without a hitch. I decided not to search Window Update for the cumulative 1803 update but wait until i was informed it was available for my PC.  So I commenced to reinstall the balance of the bought programs and it was towards the end of the list I noticed a slight sluggishness but thought nothing of it. Upon powering down I noticed that although 3 of the external usb self powered drive lights had extinguished a fourth drive light was still flickering and the computer was still running. I waited 20 minutes and as there was no change I turned the computer off by the power button. Turning on the computer again and failing to auto repair etc. the current unmountable boot volume error materialised. I did read that MS 1803 update was programmed to attempt to check for updates during boot up and also during powering down but did not think that that was the issue of the computer running for that 20 minutes plus the usb drive lights situation. Prior to all this when I was ready to update to 1709 up from 1603 a glitch occurred resulting in the inability to boot up the computer at all. I paid a repair chap to resolve it, which he did and returned the computer with the user folder intact and 1709 installed. I now tend to look at computing with apprehension rather than joy.

[Boggin]

No, you won't lose any data booting up with the USB - just don't hit the Install button on the Install screen.

You boot up with the factory reset disk so the unmountable error wouldn't come into as you aren't booting into Windows.

You would lose your personal stuff if you don't have that stuff backed up though.

There is a way of salvaging your personal stuff and that with a Ubuntu/Linux install disk, although I've never done it.

https://www.psychocats.net/ubuntucat/recovering-windows-files-with-a-ubuntu-cd-ii-getting-your-files/

A factory reset is a last resort though - see how you get on with the suggestions I've posted after booting up with the install USB.

[utbas1953]

Hello Boggin, Today I ventured to carry out your info. I have inserted the usb stick into the desktop, started the computer, tapping f11 brought up the bios. I selected the usb stick and computer booted up. Went to advanced and commands. A panel came up with the following:
'not enough memory resources are available to process this command' and the next line has X:\Sources>
I do not know how to type in the parameters to access the c drive.

[Boggin]

That is the normal cmd prompt you get in that mode as you are booted into memory.

Go back to my first reply and enter those cmds as I've listed, although I've never had that not enough memory error before, but at least you've gotten to the cmd prompt.

[utbas1953]

OK Boggin but I do not know what to type in initially to get to the c drive. What do I actually type in the following Enter bcdedit |find "osdevice" . I keep getting incorrect input.

[utbas1953]

Boggin, I have Googled again for info and tried a few re cd d: etc but to no avail. You will not believe what happened next....I have been tapping f11 to select the W10 OS on the usb stick. I did another power down and upon startup tapped f8. The desktop slowly booted up normally without a hitch and is now running at the speed of operations before the unmountable boot volume problem. W10 1803 is retained. I will power down and see if the next startup does so without a hitch. I just do not believe it after all the aggro of the failure.   

[Boggin]

That cmd should have given you a partition letter - as for the rest, perhaps it just needed a power shut down a couple of times to clear it, but glad to see that it is probably back to normal ?

[utbas1953]

Hi Boggin, When the desktop first played up the diagnosing/ attempted repair failed.  The display with the various choices did at one stage appear before the usb drive W10 was made and at that point I tried to restore back to a restore point I had made a short while before the glitch started but that failed too and the constant message I was getting was the unmountable boot volume hence my asking for info. The weird thing is that although the restore point had failed and that was a couple of days ago, when the computer tonight decide to boot up normally one of the displays that appeared during boot up was one that said the restore point had failed. Upon checking the restore points the one chosen was still intact. I just can't fathom out why I was being told the C drive was unmountable. Still, thanks for your input and I will keep that info filed. Thank you.

[Boggin]

I think Win 10 and restore points is a bit hitty missy.

I've done a restore point in the advanced boot options which returned as failed, but when I rebooted back to normal, I got a message to say it had been successful.

I tend to rely on my Macrium system images to go back in Win 10.