To disable CSM (Compatibility Support Module) in setup/BIOS, you normally need to switch your motherboard firmware to full UEFI mode and then save and reboot so the change “sticks.”

What CSM Is

  • CSM is a compatibility layer in BIOS/UEFI that lets newer boards boot old “Legacy/MBR” systems and devices.
  • Disabling it forces the system to use pure UEFI boot, which is often required for Secure Boot and Windows 11.

General Step‑By‑Step (Most PCs)

Exact wording and layout vary by brand, but the flow is usually:

  1. Power on and enter BIOS/UEFI
    • Press Del, F2, F10, Esc, or the key shown on the first boot screen repeatedly.
  2. Switch to Advanced/Expert mode
    • Many boards open in “EZ/Easy Mode”; look for an Advanced button or press F7.
  1. Go to the Boot tab or Boot menu
    • On most boards the CSM option is under a Boot section, sometimes called “CSM,” “CSM Support,” or “Compatibility Support Module.”
  1. Find and set CSM to Disabled
    • Change “CSM Support” or “Launch CSM” from Enabled/Auto to Disabled.
  1. Ensure boot drive is UEFI/GPT‑ready
    • Windows installed in Legacy/MBR often will not boot with CSM off and may need to be reinstalled or converted to GPT.
  1. Save changes and reboot
    • Use “Save changes and reset” or press F10, confirm, and let the PC restart.

Brand‑Specific Hints (Common Cases)

  • ASRock:
    • CSM is typically under Boot → CSM; disable it, save with F10, then you can enable Secure Boot from Security → Secure Boot.
  • MSI:
    • Often under Settings → Boot → CSM Support; you may need Advanced Mode first (F7).
  • Other brands (ASUS, Gigabyte, etc.):
    • CSM/Launch CSM usually lives in the Boot tab or a sub‑menu like Boot → CSM or Boot → Legacy/UEFI settings.

If You Don’t See CSM or It Won’t Disable

  • Look in a different menu
    • On some MSI boards, users found CSM under “Settings → Boot” instead of OS configuration and solved their issue there.
  • Check boot mode and disk format
    • If Windows is installed in Legacy mode on an MBR disk, the board may resist fully switching to pure UEFI without reinstalling or converting the disk to GPT.
  • Update BIOS
    • A newer firmware sometimes changes or exposes CSM and Secure Boot options.
  • Be ready for boot problems
    • Some systems fail to boot after disabling CSM, requiring either re‑enabling CSM or repairing/reinstalling Windows in UEFI/GPT mode.

Quick Forum‑Style Tip

“If you see ‘Disable CSM in setup’ and it doesn’t stick, go into BIOS, turn off CSM under Boot/CSM Support, F10 to save, reboot, then re‑enter BIOS to enable Secure Boot or adjust your boot drive if needed.”

Information gathered from public forums or data available on the internet and portrayed here.