Windows 10: laptop showing option to choose win 10 os

multiple laptops in my company suddenly showing option to choose OS during startup. this happened after windows update. the os updated from 1909 to 20h2 version. i already know how to bypass the process. my queries as below.1. why is this happening. is it due unclean update?2. few application like teams and ms office started become unstable and always hang.

:)

 

The page which shows option to choose OS was not coming in Windows 10 dual boot

THANKS IN ADVANCE

I just dual booted my laptop previously installed windows 10.

Then I got problem. The page which shows option to choose OS was not coming.Then I installed EASYbcd as suggested by some users . Then the page was shows but it only contains Windows 10. Help me please. How to come out of it.

Original title; BOOT MANAGER

 

After Win 10 Upgrade still showing Win 8.1 OS

Thank you for the response. I will answer your queries, but as you will see from my answers I will require more specific assistance from you.

• I had a Windows 8.1 PC for several years. In June or July 2015 I received the GET WIN 10 icon on my PC. Around mid August 2015 I clicked on Get Win 10, and from there the download and install happened "automatically" for the upgrade to Win 10.
• Using your steps I opened the System configuration, and discovered the following:
  
  a) in the boot tab Windows 10 is NOT set as the default. In fact, it does not even appear at all
  
  b) Windows 8 is shown as both the default and OS. Once again Win 10 is not even shown as an option.

Now that the system is clearly not showing Windows 10 whereas it does show under ALL SETTINGS\UPDATE and SYSTEM in the Control Panel, the question is simply how do I fix this problem?

 

Choose os screen is not showing

Hi.! Iam sham...i installed Phoenix os in my pc(windows 8.1) Phoenix os said to restart and restarted there not showing of choosing os option....pls.pls.pls. Help me.