Hybrid (UEFI / MBR) ISO's -- UEFI BOOT (CSM)


  1. jimbo45
    Posts : 11,247
    Windows / Linux : Arch Linux
       New #1

    Hybrid (UEFI / MBR) ISO's -- UEFI BOOT (CSM)


    Hi folks
    recently I couldn't get some newer iso's from UUPDUMP to boot using RUFUS V 10 to create bootable usb sticks when these isos are HYBRID boot (i.e they can boot either MBR or UEFI).

    However changing the BIOS options to enabling UEFI boot (CSM module) as well as UEFI then it all worked OK -- I had CSM disabled previously but hadn't needed it so far.

    Anybody know what this CSM thing is

    It's an older MOBO which can also boot MBR (legacy) but the bios setup has to be entered and changed.

    I don't see any problems on a more modern laptop

    I thought the CSM module was only something to do with UEFI boot for Windows 7 but obviously I'm wrong

    Any gurus here who can explain what it is.

    Cheers
    jimbo
      My Computer
    Quote Quote

  3. RoadBlaster
    Posts : 465
    W11X64
       New #2

    CSM

    The Compatibility Support Module (CSM) is a component of the UEFI firmware that provides legacy BIOS compatibility by emulating a BIOS environment, allowing legacy operating systems and some option ROMs that do not support UEFI to still be used. ... Most BIOSes have a keyboard shortcut to reset to factory default settings.
      My Computers
    Quote Quote

  4. NavyLCDR
    Posts : 18,432
    Windows 11 Pro
       New #3

    What @RoadBlaster stated. CSM is Legacy BIOS emulation in UEFI firmware.
      My Computer
    Quote Quote

 

  Related Discussions
Hi folks if you want to test such things as UEFI boot or even Secure boot on a VM running on older hardware that doesn't have UEFI boot it's still easily possible. On for example Linux host running KVM/QEMU a Windows VM ( This also works on...
Sometime in the fall I started getting Windows 10 update errors trying to install 1607 (the anniversary update I believe). After trying different fixes I just ignored it for a while hoping windows would come up with a fix. 6 months later and I'd...
I want to enable UEFI with Secure Boot and I do have an option to enable Secure Boot. But how can I tell if I am running UEFI firmware version 2.3.1.c ? Because to enable Secure Boot, machines must have UEFI firmware version 2.3.1.c I went to...
Hello. So i got automatic repair after changing boot order from UEFI USB KINGSTON to P1 Samsung SSD 840 EVO. I am able to get through to Windows 10 but after restart after automatic repair. So i am needing 2 boots now. Screen: 74243 And my...
Our Sites
Site Links
About Us
Windows 10 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 10" and related materials are trademarks of Microsoft Corp.

 © Designer Media Ltd
All times are GMT -5. The time now is 12:11.
Find Us




Windows 10 Forums