Question Windows 10 stuck in diagnostic mode boot

Aprillion

Prominent
Dec 22, 2020
30
0
530
0
Yesterday something very weird happened..
I had my PC on just downloading some stuff, and after an hour I found out it restarted itself in diagnostic mode and no way to boot it back up to windows anymore.
I’ve tried to do some kind of scan through cmd that didn’t want to start and I’ve tried to start the PC in safe mode, but it always starts in diagnostic mode.
I’ve tried to boot from my laptop HDD that I plugged in my main build with another windows installation and it still boots diagnostic mode.
Sad part is that windows is installed on a m.2 drive so it’s hard for me to backup my files (because my other PC’s don’t fit that drive.)
So I can’t try to re-install windows on my m.2 drive without doing a backup first.
I did try to re-install windows on my laptop drive that I plugged to it, but I got the following error message:
“Windows could not prepare the computer to boot into the next phase of installation”
(And I get errors all the time when trying to re-install windows from bootable usb).

I’m unsure what went wrong, it’s a pretty new PC with high-end hardware and cooling, never had any problems.
Booting from a working HDD is also not working and same goes for reinstalling windows.
Could this be a diagnostic mode glitch?
Anybody knows how to fix this?

Thanks in advance!
 

dwd999

Honorable
Yesterday something very weird happened..
I had my PC on just downloading some stuff, and after an hour I found out it restarted itself in diagnostic mode and no way to boot it back up to windows anymore.
I’ve tried to do some kind of scan through cmd that didn’t want to start and I’ve tried to start the PC in safe mode, but it always starts in diagnostic mode.
I’ve tried to boot from my laptop HDD that I plugged in my main build with another windows installation and it still boots diagnostic mode.
Sad part is that windows is installed on a m.2 drive so it’s hard for me to backup my files (because my other PC’s don’t fit that drive.)
So I can’t try to re-install windows on my m.2 drive without doing a backup first.
I did try to re-install windows on my laptop drive that I plugged to it, but I got the following error message:
“Windows could not prepare the computer to boot into the next phase of installation”
(And I get errors all the time when trying to re-install windows from bootable usb).

I’m unsure what went wrong, it’s a pretty new PC with high-end hardware and cooling, never had any problems.
Booting from a working HDD is also not working and same goes for reinstalling windows.
Could this be a diagnostic mode glitch?
Anybody knows how to fix this?

Thanks in advance!
The first thing I would do was figure out whether its a hardware problem or a Windows problem. For this I use a linux distro booted from a usb stick; if it boots and all the hardware appears functional then it just Windows. If you want to try this and need instructions let us know.
 
Last edited:

Aprillion

Prominent
Dec 22, 2020
30
0
530
0
The first thing I would do was figure out whether its a hardware problem or a Windows problem. For this I use a linux distro booted from a usb stick; if it boots and all the hardware appears functional then it just Windows. If you want to try this and need instructions let us know.
Thanks, will try that this week and keep you updated!
 

Aprillion

Prominent
Dec 22, 2020
30
0
530
0
The first thing I would do was figure out whether its a hardware problem or a Windows problem. For this I use a linux distro booted from a usb stick; if it boots and all the hardware appears functional then it just Windows. If you want to try this and need instructions let us know.
I have booted up Linux Ubuntu from USB succesfully with the “try ubuntu” option!

I’m now able to backup my files and ths means it’s not a hardware issue right?

Got any tips on what could be the problem or fix with windows 10 diagnostic mode?

or should I try to reinstall windows on my m.2 drive?
 

dwd999

Honorable
I have booted up Linux Ubuntu from USB succesfully with the “try ubuntu” option!

I’m now able to backup my files and ths means it’s not a hardware issue right?

Got any tips on what could be the problem or fix with windows 10 diagnostic mode?

or should I try to reinstall windows on my m.2 drive?
If you are able to back up all of your essential files then a reinstall of Windows would probably be the quickest solution. You've already wasted a lot of time allowing Windows "diagnostic mode" to try and resolve whatever problem you had and Windows has clearly failed you.
 

Aprillion

Prominent
Dec 22, 2020
30
0
530
0
If you are able to back up all of your essential files then a reinstall of Windows would probably be the quickest solution. You've already wasted a lot of time allowing Windows "diagnostic mode" to try and resolve whatever problem you had and Windows has clearly failed you.
I’ve tried to perform an install on my m.2 drive but it’s the same as before..

“Windows could not prepare the computer for the next phase of installation. To install Windows, restart the installation.”

Would unplugging all my other drives help?
My m.2 has a second partition though..
 

dwd999

Honorable
I’ve tried to perform an install on my m.2 drive but it’s the same as before..

“Windows could not prepare the computer for the next phase of installation. To install Windows, restart the installation.”

Would unplugging all my other drives help?
My m.2 has a second partition though..
Yes, unplugging all other drives does help. It appears the installer was designed by programmers who had only 1 drive in their computer and it doesn't work well with more than 1 drive. Is the second partition blank or do you still have stuff on it. The quickest and easiest thing to do would be to let the installer delete all of the partitions on your drive and then after installation is complete you could shrink the main volume and create a second volume. But for the long term it is generally not a good idea to have more than one partition on your boot drive since if windows gets messed up again you'll have to move all that stuff off before a reinstall.
 

Colif

Win 11 Master
Moderator
Jun 12, 2015
56,858
4,530
160,690
10,277
“Windows could not prepare the computer for the next phase of installation. To install Windows, restart the installation.”
it actually sounds like windows is mixed up. I seen this before, if an update or install is disrupted, windows can get stuck in a loop where if you put installer in, it says to do those steps but nothing happens on a restart. You normally need to wipe the drive and then it will let you install.

need to wipe all partitions on the m.2 and start again.

Boot from installer

On screen after language choice, pick repair pc, not install

Pick troubleshoot

Pick advanced

Pick Command Prompt

Type diskpart and press enter

Type list disk and press enter

This will show the list of drives currently attached to PC, make note of the drive number of the drive you want to wipe

If Disk 1 is the drive you want to clear, type select 1) and press enter. A message will confirm it is selected

Warning: Diskpart Erase/Clean will permanently erase/destroy all data on the selected drive. Please be certain that you are erasing the correct disk.

Once you sure its right disk, type Clean and press enter

The Command Prompt window will display the message "DiskPart succeeded in cleaning the disk". Close out of the Command Prompt window by clicking the red X in the upper right hand corner.

restart installer and try again.

having 1 drive in will help.
 

Aprillion

Prominent
Dec 22, 2020
30
0
530
0
Yes, unplugging all other drives does help. It appears the installer was designed by programmers who had only 1 drive in their computer and it doesn't work well with more than 1 drive. Is the second partition blank or do you still have stuff on it. The quickest and easiest thing to do would be to let the installer delete all of the partitions on your drive and then after installation is complete you could shrink the main volume and create a second volume. But for the long term it is generally not a good idea to have more than one partition on your boot drive since if windows gets messed up again you'll have to move all that stuff off before a reinstall.
It’s installing now!
Will set this thread to solved if everything goes well!
 

Aprillion

Prominent
Dec 22, 2020
30
0
530
0
it actually sounds like windows is mixed up. I seen this before, if an update or install is disrupted, windows can get stuck in a loop where if you put installer in, it says to do those steps but nothing happens on a restart. You normally need to wipe the drive and then it will let you install.

need to wipe all partitions on the m.2 and start again.

Boot from installer

On screen after language choice, pick repair pc, not install

Pick troubleshoot

Pick advanced

Pick Command Prompt

Type diskpart and press enter

Type list disk and press enter

This will show the list of drives currently attached to PC, make note of the drive number of the drive you want to wipe

If Disk 1 is the drive you want to clear, type select 1) and press enter. A message will confirm it is selected

Warning: Diskpart Erase/Clean will permanently erase/destroy all data on the selected drive. Please be certain that you are erasing the correct disk.

Once you sure its right disk, type Clean and press enter

The Command Prompt window will display the message "DiskPart succeeded in cleaning the disk". Close out of the Command Prompt window by clicking the red X in the upper right hand corner.

restart installer and try again.

having 1 drive in will help.
I just deleted all the m.2 partitions through the installer and it’s installing now, even though I still got my second m.2 connected on my mobo.

Cheers!
 

dwd999

Honorable
I just deleted all the m.2 partitions through the installer and it’s installing now, even though I still got my second m.2 connected on my mobo.

Cheers!
For safety's sake, after installation is complete just check your second m.2 and make sure the installer did not put any of the essential boot up files on the second m.2. As long as the second m.2 remains totally blank you should be okay and able to avoid future boot up problems.
 

Aprillion

Prominent
Dec 22, 2020
30
0
530
0
For safety's sake, after installation is complete just check your second m.2 and make sure the installer did not put any of the essential boot up files on the second m.2. As long as the second m.2 remains totally blank you should be okay and able to avoid future boot up problems.
The installation worked!
Installed on my main m.2 without partitions this time.
Second m.2 hasn’t changed and wasn’t empty too, there even was another windows installation on there too, and for the first time ever it showed the dual boot screen at startup had that never before.
Thanks for your help!
 

dwd999

Honorable
The installation worked!
Installed on my main m.2 without partitions this time.
Second m.2 hasn’t changed and wasn’t empty too, there even was another windows installation on there too, and for the first time ever it showed the dual boot screen at startup had that never before.
Thanks for your help!
But you need to be aware that with the 2 drives linked together in dual boot mode they will remain linked so you can not change the 2nd drive. There is a procedure to unlink drives from dual boot so if you need or want to do that you could start a new thread on that.
 
Reactions: Aprillion

Aprillion

Prominent
Dec 22, 2020
30
0
530
0
But you need to be aware that with the 2 drives linked together in dual boot mode they will remain linked so you can not change the 2nd drive. There is a procedure to unlink drives from dual boot so if you need or want to do that you could start a new thread on that.
Alright thanks, how do I set this thread to solved?
 

ASK THE COMMUNITY