Question "Reboot and select proper boot device" - running out of ideas

Dec 4, 2020
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My Win10 is taking a long time to boot despite having SSD. When I set my SSD as the first boot option in BIOS, I get the "Reboot and select proper boot device" error. It only works if I revert to Windows Boot Manager as the first option, but it takes 13 to 17 seconds to load.

I do have an external HDD connected and it was my prime suspect, but unplugging it makes no difference whatsoever.

Partitions look like this.

What I tried so far:
  • updating Windows and all drivers - checked
  • turning off fast startup - checked
  • disabling all but essential programs on startup - checked
  • AHCI is set, not IDE - checked
My configuration:
Biostar X470GTQ
AMD Ryzen 5 3400G
SSD M.2 250GB Kingston SKC2000
Asus Dual series Radeon RX 580 OC edition
RAM Kingston KVR32N22D8/16

Ask anything you need.
 
check windows integrity
open the command prompt as administrator and type DISM /Online /Cleanup-Image /RestoreHealth
https://www.lifewire.com/how-to-open-an-elevated-command-prompt-2618088
https://answers.microsoft.com/en-us/windows/forum/windows_10-update/system-file-check-sfc-scan-and-repair-system-files/bc609315-da1f-4775-812c-695b60477a93


clean boot
https://support.microsoft.com/en-us/help/929135/how-to-perform-a-clean-boot-in-windows

check the SSD for errors with its manufacturer´s tool

was windows installed freshly with this system?

Do you mean 13seconds from power on to windows or rebooting windows?

Is your system running GPT or MBR ?
https://www.windowscentral.com/how-convert-mbr-disk-gpt-move-bios-uefi-windows-10#convert_mbr_gpt_windows10

after conversion enable fast boot in bios
 
Dec 4, 2020
3
0
10
0
check windows integrity
open the command prompt as administrator and type DISM /Online /Cleanup-Image /RestoreHealth
https://www.lifewire.com/how-to-open-an-elevated-command-prompt-2618088
https://answers.microsoft.com/en-us/windows/forum/windows_10-update/system-file-check-sfc-scan-and-repair-system-files/bc609315-da1f-4775-812c-695b60477a93


clean boot
https://support.microsoft.com/en-us/help/929135/how-to-perform-a-clean-boot-in-windows

check the SSD for errors with its manufacturer´s tool

was windows installed freshly with this system?

Do you mean 13seconds from power on to windows or rebooting windows?

Is your system running GPT or MBR ?
https://www.windowscentral.com/how-convert-mbr-disk-gpt-move-bios-uefi-windows-10#convert_mbr_gpt_windows10

after conversion enable fast boot in bios
Thank you for reaching out to help.

I tried that RestoreHealth command, it executed but still no difference in boot time. The same thing happened with a clean boot - I did everything, step by step, still the same. Kingston SSD Manager gave me no errors.

Windows was installed some 4-5 months ago when I bought the computer. It had this issue from the start, but with the whole COVID situation going on, I never had time to start dealing with it. Windows is licensed and everything is updated.

13-17 seconds is that Last BIOS Time (Task Manager > Startup). It actually takes about 45 seconds from power on or rebooting until the Lock Screen appears, which is definitely too long.

Disk Management says that SSD is using GPT - however, when I tried using mbr2gpt /validate /allowFullOS command it told me that "Disk layout validation failed for disk 0". Now, I never made any partitions and have only C: but Disk Management shows that there are 3 additional ones (see screenshot here), so I'm guessing that Windows installation created them when installing the system, but maybe they are the ones causing the problem. The external drive is MBR but as I said, it's not making any difference whether it's plugged in or not and I tried it numerous times.

Edit This is what mbr2gpt /validate /allowFullOS gave me:

C:\WINDOWS\system32>mbr2gpt /validate /allowFullOS
MBR2GPT: Attempting to validate disk 0
MBR2GPT: Retrieving layout of disk
MBR2GPT: Validating layout, disk sector size is: 512 bytes
Disk layout validation failed for disk 0
 
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the command will only work for mbr partitions, don't worry about the three other partitions, these are needed for windows to work properly

update the bios of your motherboard

enable the xmp profile for the ram
 
Dec 4, 2020
3
0
10
0
the command will only work for mbr partitions, don't worry about the three other partitions, these are needed for windows to work properly

update the bios of your motherboard

enable the xmp profile for the ram
Ok, I updated the bios just now, installation went smoothly but now bios doesn't see my ssd anymore. To be honest, I'm a bit freaked out and would really appreciate advice how to get it back.

Edit: It is visible in NVMe Configuration, but nowhere else, so I can't use it to boot. How do I detect it?
 
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