Black screen instead of bootloader, then start

Hello,

I had Windows 10 installed on one partition, and then installed Windows 10 on another partition. The first time I restarted the laptop after the installation finished, I got the "Choose an operating system" (you know, the blue menu with white font) menu (with the two installations) and the 30 seconds time before the auto choose. But then, after the new Windows 10 started, and after the drivers were automatically installed and everything else set up, I restarted the laptop again, and this time there was no "Choose an operating system"" menu - instead there was black screen (with display backlight turned on of course) for some time (probably the 30 seconds) and then the laptop booted into the newly installed Windows 10 (it is set as default now). I tried restarting the laptop several times to confirm that this is the issue. I tried pressing the F12 button at boot, which brings another Windows menu (also blue) from which you can choose the option for the "Choose an operating system" menu. I chose that option, and the "Choose an operating system" menu came up and I could choose between the two installations (the older installation is set as second - non-default choice).

So, I'm very happy that something worse didn't happen, but how can I fix the black screen during the automatic (at laptop turn on) "Choose an operating system" menu. Without breaking something else meanwhile.

Version number: 20H2
Laptop model: ASUS X509JA

Thanks in advance.

Hello manvas and welcome to TF ,

Boot to the working Windows, install MR:
Backup and Restore with Macrium Reflect
make a MR Rescue USB, then boot from it and try the repair option.

Let me know how that works out the to resolve the issue.

steve108 said:

Hello manvas and welcome to TF ,

Boot to the working Windows, install MR:
Backup and Restore with Macrium Reflect
make a MR Rescue USB, then boot from it and try the repair option.

Let me know how that works out the to resolve the issue.

I don't know if you got me right.
I can boot in both Windows installations, but the bootloader (for the dual-boot) doesn't exactly show at the beginning by default - instead, there's a black screen for some times (probably the 30 seconds that are supposed to pass with the bootloader shown) and then the OS (default) anyway. However, the bootloader can be accessed via the Windows start menu that appears when you press F12 on my laptop (it's a Windows menu, not a menu integrated in the laptop). But I want the laptop to normally actually show the menu at the start (the "Choose opearating system" menu).

I take it this is some unusual bug, so I don't know whether Macrium will fix the issue.

Check the time in system properties for both: Change Time to Display Operating Systems at Startup in Windows 10

OPTION TWO
To Change Display OS Timeout in Startup and Recovery
Option 2, step 3
from tutorial

Also check
OPTION THREE
To Change Display OS Timeout in System Configuration (msconfig)

Look at this one also:
Choose Default Operating System to Load at Startup in Windows 10

steve108 said:

Also check
OPTION THREE
To Change Display OS Timeout in System Configuration (msconfig)

You mean check whether the time is set, and whether it is set to 30 seconds everywhere?
Anyway, here's a SS of the partitions if it helps: https://i.snipboard.io/5I2uoj.jpg

Run bcdedit command from the command prompt and post your output please.

steve108 said:

Run bcdedit command from the command prompt and post your output please.

Thanks for the screenshot. Do bcdedit and post output first.