How to Turn Off CSM in Your BIOS

What CSM is and why you might need to disable it

CSM stands for Compatibility Support Module. It is a BIOS feature that lets your computer run older software and hardware that was built for an older system standard. When CSM is on, your motherboard pretends to be an older machine so that old programs and devices will work. When you turn it off, your computer runs in a newer, stricter mode called UEFI-only.

You need to disable CSM when you are installing a modern operating system on a new drive and want to use the newer boot method, or when CSM is causing conflicts with new hardware or software. Some newer operating systems run faster or more securely with CSM off. If you are having boot problems, driver conflicts, or installation failures on a newer computer, disabling CSM is often the first thing to try.

The risk of turning CSM off is that very old devices or programs may stop working. If you have old USB devices, printers, or software from more than ten years ago, test them after you make the change. Most people with computers from the last five years will see no problems at all.

Key Takeaways

CSM is a compatibility mode that makes new computers behave like old ones; turning it off makes your system run in modern UEFI mode instead.
You access CSM in the BIOS setup screen, which you reach by restarting your computer and pressing a specific key during startup — usually Delete, F2, F10, or F12 depending on your motherboard brand.
The exact menu location and wording varies by manufacturer, but you are looking for a setting called CSM, Compatibility Support Module, Legacy Boot, or Boot Mode.
After you disable CSM, your computer will boot differently and may not recognize old external devices until you restart.
If your system will not start after disabling CSM, you can turn it back on using the same process.

How to enter BIOS and find the CSM setting

Restart your computer completely. As it powers back on, watch the screen for a message that says "Press [key] to enter Setup" or "Press [key] for BIOS." The key varies by manufacturer: common ones are Delete, F2, F10, F12, or Escape. You have only a few seconds to press it, so if you miss it, restart again and watch more carefully. If you do not see a message, try Delete or F2 first — these work on most modern boards.

Once you are in the BIOS setup screen, you will see a menu with options like Main, Advanced, Boot, Security, and Save & Exit. The CSM setting is usually in the Boot menu, but some manufacturers put it under Advanced. Look for a tab or menu item labeled Boot and press Enter or click it. If you do not see CSM there, try Advanced next.

Inside the Boot menu, look for an option called CSM, Compatibility Support Module, Legacy Boot, Legacy Mode, or Boot Mode. The exact name depends on your motherboard maker — ASUS, MSI, Gigabyte, and others use slightly different wording. When you find it, the current setting will show either "Enabled" or "On" (CSM is active) or "Disabled" or "Off" (CSM is inactive).

Disabling CSM step by step

Highlight the CSM setting by moving to it with your arrow keys or mouse. Press Enter or click on it. A small menu will appear showing your options, usually "Enabled" and "Disabled." Use the arrow keys or mouse to select "Disabled," then press Enter to confirm the change.

Some BIOS screens also show related settings nearby, such as "Boot Mode" or "UEFI Boot." If you see a Boot Mode option set to "Legacy," change that to "UEFI" at the same time. These settings work together, and having them mismatched can cause boot problems. Once CSM is set to Disabled and Boot Mode is set to UEFI, move to the Save & Exit menu.

In the Save & Exit menu, select "Save Changes and Exit" or "Exit and Save Changes." The exact wording varies, but the intent is clear. Your computer will restart automatically. Do not turn off the power during this restart — let it complete on its own. The first boot after disabling CSM may take longer than usual as the system adjusts.

What to expect after disabling CSM

Your computer will restart and boot into your operating system normally. If you have Windows or Linux installed, it should load as usual. The change is invisible to you in daily use — you will not see a notification or message saying CSM is off. The system straightforward runs in UEFI mode instead of the older compatibility mode.

If you have external USB devices like printers, external hard drives, or older USB hubs, they may not be recognized when ready after the restart. Unplug them and plug them back in. Most will work fine. If an old device does not work after you plug it back in, that device may require CSM to be on — you can turn CSM back on using the same steps if needed.

If your computer will not start or gets stuck on a black screen, CSM may have been required for your current setup. Restart, enter BIOS again, and turn CSM back on. This is not harmful — you are straightforward reverting the change. Once CSM is back on, your system should boot normally again.

When to turn CSM back on

Turn CSM back on if your computer will not boot after you disabled it, if critical hardware stops working, or if you need to run very old software that requires legacy mode. The process is identical to disabling it: enter BIOS, find the CSM setting, change it to Enabled, save, and exit.

If you disabled CSM to install a new operating system and the installation failed, you may need CSM on for that particular installation. Some older Windows versions or Linux distributions expect legacy mode. Check the documentation for your operating system to see whether it requires UEFI or supports both modes.

There is no penalty for turning CSM on and off multiple times. It is a normal troubleshooting step. If you are uncertain whether you need it off, start with it on and only disable it if you are having specific problems that CSM might cause.

Frequently Asked Questions

Will disabling CSM make my computer faster?

Possibly, but usually not noticeably. UEFI mode (CSM off) can boot slightly faster than legacy mode, and some newer security features work better without CSM. The difference is usually seconds at most. Speed gains are real but small for most people.

Do I need to reinstall Windows after I disable CSM?

Not if Windows is already installed. If Windows was installed with CSM on, it will usually boot fine with CSM off. However, if you are installing Windows fresh, you should have CSM off before you start the installation so the system installs in UEFI mode from the beginning.

What if I cannot find the CSM setting in my BIOS?

Your motherboard may not have CSM, which is common on very new boards that only support UEFI. Check your motherboard manual or the manufacturer's website to confirm. You can also search for your exact motherboard model plus "CSM" to see if the feature exists on your board.

Can I disable CSM if I have an old hard drive with Windows on it?

If the drive was installed with CSM on, disabling CSM may prevent it from booting. Test it first with CSM still on. If you want to use that drive with CSM off, you may need to reinstall Windows or use a tool to convert the drive from legacy to UEFI mode — this is advanced and risky, so only attempt it if you have a backup.

Is it safe to change CSM settings?

Yes. CSM is a standard BIOS setting designed to be changed. The worst outcome is that your computer will not boot, but you can always turn it back on using the same steps. You cannot damage hardware by changing this setting.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.