How to Enable All Cores in Windows 11

Windows 11 normally uses all of your processor’s cores automatically, but sometimes the system is configured to use only a subset—often due to a setting called “Number of processors” in the System Configuration tool (msconfig). This guide shows you how to check and, if needed, enable all cores so your CPU can run at its full potential. You’ll need administrator access to your PC, and it’s wise to create a restore point before making any changes.

What You’ll Need

• A Windows 11 PC with administrator privileges
• Basic comfort navigating System Configuration and Device Manager
• Optional: a system restore point (recommended for safety)

Step-by-Step

1. Open System Configuration. Press Win + R to open the Run dialog. Type msconfig and press Enter. If prompted by User Account Control, click Yes.
2. Go to the Boot tab. In the System Configuration window, click the Boot tab at the top.
3. Select your operating system. If you have multiple OS entries (e.g., dual boot), make sure your current Windows 11 installation is highlighted (usually the first one).
4. Click Advanced options. This opens a small dialog titled BOOT Advanced Options.
5. Uncheck “Number of processors”. If the checkbox is ticked, uncheck it. This tells Windows to use all available cores. If it’s already unchecked, your system is already set to use all cores—skip to step 8.
6. Also uncheck “Maximum memory”. If this is checked, it can limit RAM usage. Uncheck it as well, unless you intentionally set it for troubleshooting.
7. Click OK to close the BOOT Advanced Options, then click Apply and OK in the main window.
8. Restart your PC. Windows will ask you to restart. Save any work and restart. Your system will now boot using all processor cores.
9. Verify the change. After restarting, open Task Manager (Ctrl + Shift + Esc), go to the Performance tab, and click on CPU. In the lower-right, you should see “Logical processors” matching your CPU’s full thread count. For example, a 6-core/12-thread CPU should show 12 logical processors.

Common Mistakes

• Leaving the checkbox ticked with a lower number. If you tick “Number of processors” and select, say, 4 on an 8-core CPU, you’re intentionally limiting it. Always leave it unticked for full performance.
• Confusing cores with logical processors. “Cores” are physical, while “logical processors” include Hyper-Threading. Windows uses both automatically.
• Expecting a huge speed boost. If your OS was already using all cores, you won’t see a difference. This fix only helps if the setting was previously limited.
• Forgetting to restart. The change only takes effect after a full restart.

Tips

• Use the default settings. For most users, the best configuration is to leave both “Number of processors” and “Maximum memory” unchecked. Windows manages these automatically.
• Check your BIOS/UEFI. If Windows still doesn’t see all cores after this change, your BIOS may have core disabling enabled (often under CPU Configuration). Enter BIOS (usually by pressing Del or F2 during boot) and look for options like “Core Ratio” or “Active Cores”—set them to “Auto” or “All”.
• Update your chipset drivers. Outdated chipset drivers can sometimes cause Windows to misdetect cores. Visit your motherboard or laptop manufacturer’s support page for the latest drivers.
• Use PowerShell to verify. You can also check core count with a command: press Win + X and select “Terminal (Admin)”, then run wmic cpu get NumberOfCores,NumberOfLogicalProcessors.

Troubleshooting

After restart, Task Manager still shows fewer cores than expected. First, re-open msconfig and confirm the checkbox is still unticked. If it is, the issue may lie elsewhere: check your BIOS for core disabling, and make sure your Windows is fully updated. Also, run sfc /scannow in an elevated Command Prompt to repair system files.

Windows fails to boot after the change. This is rare, but if it happens, boot into Safe Mode (hold Shift while clicking Restart, then navigate to Troubleshoot > Advanced options > Startup Settings). In Safe Mode, open msconfig and re-tick the checkbox, then restart normally. You can also use System Restore if you created a restore point.

No change in performance. Remember, this setting rarely affects performance in a noticeable way. If your cores were already all enabled, you won’t see a difference. If you’re experiencing slowdowns, the cause is likely something else—check background processes, thermal throttling, or power settings.

Frequently Asked Questions

Does Windows 11 automatically use all cores?

Yes, by default Windows 11 uses all available cores. The msconfig setting is only a limitation if someone manually changed it.

Will enabling all cores improve gaming performance?

Only if your system was previously limited. Most games benefit from more cores, but the difference is minimal if you were already using all cores. Other factors like GPU and RAM are often more important.

Is it safe to enable all cores?

Yes. It’s the default configuration and is completely safe. The CPU is designed to run with all cores active.

Can I disable some cores to save power?

You can, but Windows already manages core parking and power states efficiently. Manually disabling cores via msconfig is not recommended because it can cause instability and doesn’t save significant power.

Why does my CPU show more logical processors than cores?

That’s Hyper-Threading (Intel) or SMT (AMD). Each physical core can handle two threads, so a 6-core CPU with Hyper-Threading shows 12 logical processors. Windows uses both.

Do I need to change BIOS settings as well?

Usually not. If Windows already sees all cores after the msconfig fix, BIOS is fine. Only if cores are still missing should you check BIOS for core disabling options.

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