Windows 10: Csm or legacy options unavailable in bios.

please help me my bios systeam have no csm or legacy options for that i cant install windows 10 by bootable usb drive.

Device:Asus

Model:x509fb

:)

 

Bios

That is a UEFI Bios, which has less options than old Legacy BIOS.

In BIOS try disabling Secure Boot and enabling CSM, then boot your system to make sure it boots

Then go back into you BIOS and you should be able to change to boot order so you can install Windows 8.1 and dual boot

Ideally what you need to do is a complete re-install to successfully create a Dual Booting System
(Older OS should be installed first):

• Backup all your data
• In BIOS disable Secure Boot and enabling CSM and if available enable Legacy BIOS
• Remove all partitions on your HDD
• Create 2 Empty partitions of a suitable size for each Operating System
• Then Install both Operating Systems, Windows 8.1 first, then Windows 10
  

 

Difficulty setting BIOS to boot in Legacy mode

Hi,

It is possible that Win 8 didn't have that EFI partition, but it probably did...

If it did not, and you upgraded to Win 10, it would not have been added...

A clean install is a different animal, especially if your machine was set for UEFI when you did it... If you could set the machine to legacy for instance, it is doubtful that the EFI partition would be there...

Btw... if you get the chance, look to see if your BIOS has a setting concerning "CSM" or similar... It would probably be in the same area where you select Legacy...

Here is a note I found concerning that setting...

Quote...

The UEFI boot manager is able to load legacy BIOS environment using the Compatibility Support Module (CSM). This module is able to emulate
legacy BIOS environment and allow booting legacy operating systems or new operating systems which were installed without UEFI boot loader

 

Powercolor RX480 BIOS required

Find the unverified bios option.