Windows 10 Installation Failed: Can not boot PC

[Guest]

Hi there.

So I tried to upgrade to W10 from W8.1 today. Big mistake. I left the computer and when I came back an error message had appeared:
"Your computer failed to start.
\Boot\BCD 0xc0000255"

I have tried all sorts of things.
Reset this PC returns locked,
diskpart, bootrec from both 8.1 and 10 medias doesn't work, and I think I managed to mess it up even more.

Now when I boot it says:
"No valid partition table"
and I can't install 8.1 again because my drive doesn't show up.
Is there something I can do to at least get my files back? How do I continue?
I'm really scared that I've done something not-good...

 

[watrhous]

Hi there.

So I tried to upgrade to W10 from W8.1 today. Big mistake. I left the computer and when I came back an error message had appeared:
"Your computer failed to start.
\Boot\BCD 0xc0000255"

I have tried all sorts of things.
Reset this PC returns locked,
diskpart, bootrec from both 8.1 and 10 medias doesn't work, and I think I managed to mess it up even more.

Now when I boot it says:
"No valid partition table"
and I can't install 8.1 again because my drive doesn't show up.
Is there something I can do to at least get my files back? How do I continue?
I'm really scared that I've done something not-good...

Go here https://www.microsoft.com/en-us/software-download/windows10
and download the Windows 10 repair tool and install it to a usb. Boot your machine to the USB (ask if you dont know how) and this will either get you Windows 10 repaired or give you options to repair.

You may need to run "bootrec /fixboot" from the command prompt. Lets see.

 

[Guest]

Hi, thanks for the speedy answer.
I have indeed downloaded the W10 .iso and tried to repair/reset the PC, but it says that my computer drive is 'locked' and that I have to unlock it...
I've also tried to run the bootrec commands (fixmbr, fixboot and rebuildbcd). It always responded that there's 0 Windows installations on the drive, until it somehow came through successful (because I wrongly executed it I believe), but I still couldn't boot because of "No valid partition table".

 

[watrhous]

Hi, thanks for the speedy answer.
I have indeed downloaded the W10 .iso and tried to repair/reset the PC, but it says that my computer drive is 'locked' and that I have to unlock it...
I've also tried to run the bootrec commands (fixmbr, fixboot and rebuildbcd). It always responded that there's 0 Windows installations on the drive, until it somehow came through successful (because I wrongly executed it I believe), but I still couldn't boot because of "No valid partition table".

I do not have an answer for "No valid partition table". You can back up your data and clean reinstall with the USB tool.
Or, if you aren't concerned about loosing data/programs then I would just reinstall with the Win10 tool. It should give you an option at the load up to install. The key should be embedded in your main board. You will lose everything but it will be a clean install.

I just reinstalled Win8 witht he same method and immediately after I installed it offered me a Win10 upgrade. It did not requires hours of updates. This is also an option if the Win10 fails. Sorry I couldn't be more help.

 

[Guest]

Thanks again for the answer.
Since this seems like a complex issue and I've apparenty screwed it up even more, I'm going to do as you say and reinstall Windows completely. However I wanted to atleast try to get some files back from my drive so I downloaded Linux Mint on a USB drive. The plan was to move some of the files from the Main drive to my other.
Linux worked but I could not open the drive with the "corrupt" Windows installation on it. It had 111gb of unallocated space and no partitions. Linux wanted me to create a 'partitions table' but that required me to format the drive. Do you think there's a way to recover some files from the drive before I format?

 

[watrhous]

Thanks again for the answer.
Since this seems like a complex issue and I've apparenty screwed it up even more, I'm going to do as you say and reinstall Windows completely. However I wanted to atleast try to get some files back from my drive so I downloaded Linux Mint on a USB drive. The plan was to move some of the files from the Main drive to my other.
Linux worked but I could not open the drive with the "corrupt" Windows installation on it. It had 111gb of unallocated space and no partitions. Linux wanted me to create a 'partitions table' but that required me to format the drive. Do you think there's a way to recover some files from the drive before I format?

If i need something off a bad drive i plug it into an external usb drive housing or open sata port on our server. Then i just search the directory for the files & copy them over. Perhaps someone else here has a better suggestion but thats how I do it.

 

[Guest]

The drive shows up in Linux but I can't access the files as it has no partitions, just a bunch of unallocated space. The solutions you've provided does sound a bit out of reach for me. Do you think formatting the drive adds the partitions/resets the drive so it becomes completely useable again?

 

[watrhous]

The drive shows up in Linux but I can't access the files as it has no partitions, just a bunch of unallocated space. The solutions you've provided does sound a bit out of reach for me. Do you think formatting the drive adds the partitions/resets the drive so it becomes completely useable again?

formatting the drive will wipe it clean of your data IF indeed your data is still there. If you are not concerned about your data then just reinstall Windows 10 with and you will be given the option to delete partitions and format the drive in doing so.

 

[Guest]

The drive shows up in Linux but I can't access the files as it has no partitions, just a bunch of unallocated space. The solutions you've provided does sound a bit out of reach for me. Do you think formatting the drive adds the partitions/resets the drive so it becomes completely useable again?

formatting the drive will wipe it clean of your data IF indeed your data is still there. If you are not concerned about your data then just reinstall Windows 10 with and you will be given the option to delete partitions and format the drive in doing so.

So I decided to try to format the drive and clean install W10, and after a few hiccups I managed to get it up and running. I did not get my files back because I found the solutions to be very time/money consuming and I needed my PC as soon as possible. I thank you for your quick responses and I'll make sure to post if I ever need help again.

 

[watrhous]

The drive shows up in Linux but I can't access the files as it has no partitions, just a bunch of unallocated space. The solutions you've provided does sound a bit out of reach for me. Do you think formatting the drive adds the partitions/resets the drive so it becomes completely useable again?

formatting the drive will wipe it clean of your data IF indeed your data is still there. If you are not concerned about your data then just reinstall Windows 10 with and you will be given the option to delete partitions and format the drive in doing so.

So I decided to try to format the drive and clean install W10, and after a few hiccups I managed to get it up and running. I did not get my files back because I found the solutions to be very time/money consuming and I needed my PC as soon as possible. I thank you for your quick responses and I'll make sure to post if I ever need help again.

that's excellent news! Sorry to hear about the data loss. Good luck with Win10.