Windows 10: UEFI Question

I use Windows 10, i installed windows with UEFI, i need to install an os alongside windows, will windows 10 still boot after i change it from "UEFI" to "Legacy Support UEFI First"

:)

 

Quick question about UEFI before installing Windows 10


Make sure you have only one HD/SSD connected to your PC so temporarily disconnect the rest during installation.

1. Disable CSM & Disable Secure boot.
2. Find out which function key to invoke Boot Menu then boot up your PC with the Installation USB connected.
3. Boot up your PC and keep tapping with the Function key in step 3 to display the Boot Menu.
4. From Boot Menu, there are 2 options for Legacy(MBR) and UEFI. Select UEFI
   
   
   
5. On the first screen, hold down SHIFT key and press F10, type:
   dispart
   select disk 0
   clean
   exit
   exit
6. Click Next, select Customize then continue the installation

 

Windows 10 update with custom UEFI driver?

Hello Jonathan White,

Thank you for writing to Microsoft Community Forums.

To have a better clarity on the issue and guide you accordingly, respond to the questions listed below:

1. When you say it gets into UEFI shell, does it take you to UEFI boot options?
   
2. Are you referring to Windows updates or Windows installation?
   
3. What is the make and model of the computer?
   
4. What happens when you try to boot to the desktop? Do you see any error message while booting?
   

Also, I suggest you to go through the article on
how to post a question on Microsoft Community.

We await your response.

Regards,

Mala.S

Microsoft Community - Moderator

 

AsRock Z77 Pro3 - AHCI? UEFI?

UEFI is a new standard of bios design, so that would probably be what the BIOS has listed as the first boot option, where ACHI is a mode that SATA controllers run, and that is probably listing drives by order of first to last by port order. Not sure why it would list that way (if my guess is right as to how/why it is listing the drives).