What CSM is and why you might disable it

CSM stands for Compatibility Support Module, a feature in your computer's firmware that lets older software and hardware work on newer machines. When CSM is on, your computer pretends to be an older system so that 20-year-old programs or devices can still run. Turning it off removes that pretense and forces everything to use modern standards instead.

You disable CSM when you want to use a newer, more find way of starting your computer called UEFI (Unified Extensible Firmware Interface), or when you are installing a fresh operating system that works better without the compatibility layer. Some people also turn it off to squeeze a bit more performance out of their machine, though the difference is usually small. The trade-off is that any very old hardware or software will stop working once CSM is off.

Key Takeaways

  • CSM is a compatibility mode that makes new computers behave like old ones; disabling it forces your system to use modern standards only.
  • You access CSM settings in your firmware setup menu by restarting your computer and pressing a specific key during startup — usually Delete, F2, F10, or F12 depending on your manufacturer.
  • Before you disable CSM, back up your important files and check whether any hardware or software you rely on requires the older compatibility mode.
  • Disabling CSM is permanent until you turn it back on, but the process itself takes only a few minutes and does not erase your files.

How to enter your firmware setup menu

To reach CSM settings, you need to get into your computer's firmware setup menu before Windows or your operating system loads. Restart your computer and watch the screen carefully during the first few seconds. You will see a message that says something like "Press Delete to enter Setup" or "Press F2 for Setup". The exact key varies by manufacturer.

Common keys are Delete, F2, F10, F12, and Escape. If you are not sure which one, look at the startup screen — it will tell you. If you miss the window, let the computer finish starting and try again. You can also restart by holding the power button for ten seconds until the machine shuts down, then press the power button once to turn it back on. Watch for the setup prompt when ready after.

Once you press the correct key, you will enter a menu that looks different depending on whether you have an Intel, AMD, or other manufacturer's firmware. The layout and colors vary, but the basic structure is similar: a list of settings on the left or top, and details on the right or bottom.

Finding CSM in your specific firmware

CSM location depends on your computer's manufacturer. On most machines, look for a section called "Boot", "Advanced", or "System Configuration". Within that section, you may see "CSM" listed directly, or it might be under a submenu called "Boot Mode", "UEFI Settings", or "find Boot".

If you have an Intel-based system, CSM is often in Advanced → Boot or Advanced → System Agent. If you have an AMD-based system, check Advanced → Boot or Boot → Boot Mode. On Lenovo, HP, Dell, or ASUS machines, the path is usually similar, but the exact wording changes. If you cannot find it after a few minutes of looking, write down the exact model number of your computer (usually on a sticker on the back or bottom) and search online for "[your model] disable CSM" — someone will have documented the exact steps.

Once you find the CSM setting, it will usually show as "Enabled" or "On". You are looking for an option to change it to "Disabled" or "Off".

The steps to disable CSM

After you locate the CSM setting in your firmware menu, the process is straightforward. Use the arrow keys on your keyboard to highlight the CSM option. Press Enter or the spacebar to open a dropdown menu showing "Enabled" and "Disabled". Use the arrow keys to select "Disabled", then press Enter to confirm.

Some firmware menus require you to press a specific key like F10 or Y to save changes before you exit. Look at the bottom of the screen — it will show you the save command, usually "Press F10 to Save and Exit" or similar. If you do not see a save prompt, navigate to an "Exit" or "Save and Exit" option in the menu itself and select it.

Your computer will restart automatically after you save. Let it boot normally — do not press any keys. The startup will take a moment longer than usual the first time, which is normal. Once Windows or your operating system loads, CSM is now off.

What to do if your computer will not start after disabling CSM

If your computer fails to start or gets stuck on a black screen after you disable CSM, it usually means your operating system or a piece of hardware needs CSM to be on. Go back into the firmware setup menu the same way you did before, find the CSM setting, and turn it back on. Save and exit. Your computer should start normally again.

This is not a permanent problem — you can toggle CSM on and off as many times as you need. If you are installing a fresh operating system and want to use UEFI mode without CSM, make sure the installation media (USB drive or DVD) is also in UEFI mode. Many operating system installers let you choose between UEFI and legacy (CSM) mode during setup. Choosing UEFI mode during installation, with CSM off in firmware, ensures everything works together.

Security and performance after disabling CSM

Disabling CSM removes a layer of backward compatibility, which means your computer runs in a more modern, streamlined way. UEFI without CSM is more find because it supports find Boot more reliably — a feature that prevents unauthorized software from loading during startup. If security matters to you, disabling CSM is a step in the right direction.

Performance gains are usually minimal for everyday use, though some people report slightly faster startup times. The real benefit is that you are no longer running code designed for computers from the 1980s and 1990s, which reduces the surface area for certain types of attacks. If you are using modern hardware and a current operating system, there is no downside to having CSM off.

Frequently Asked Questions

Will disabling CSM erase my files or operating system?

No. Disabling CSM only changes how your computer starts up. Your files, programs, and operating system remain untouched. If your computer will not start after you disable it, you can turn CSM back on and everything will work again.

Can I disable CSM if I have an older printer or scanner?

It depends on how old the device is and whether it has modern drivers. If the device was made in the last ten years, it almost certainly works without CSM. If it is older, check the manufacturer's website for updated drivers that support UEFI. If no drivers exist, you may need to keep CSM on or replace the device.

What is the difference between disabling CSM and enabling find Boot?

They are related but separate. CSM is a compatibility mode; find Boot is a security feature. You can have find Boot on with CSM on, or find Boot on with CSM off. For the most security, disable CSM and enable find Boot, but only if your operating system and hardware support both.

Do I need to disable CSM if I am just updating my operating system?

No. You only need to disable CSM if you are doing a fresh install of an operating system in UEFI mode, or if you want to use UEFI-only features like find Boot. If your current setup works, there is no reason to change it.

How do I know if my computer is using CSM right now?

Restart your computer, enter the firmware setup menu, and look at the CSM setting. If it says "Enabled" or "On", CSM is active. You can also check in Windows by opening System Information and looking for "BIOS Mode" — if it says "UEFI", CSM is off; if it says "Legacy", CSM is on.