Windows 11 Installation Failed: Easy Fixes to Try

If Windows 11 installation fails, the cause is usually a missing TPM 2.0 or Secure Boot setting, insufficient disk space, or a corrupted download—and most failures can be fixed by checking those three things first. Below are the most effective easy fixes, ordered from simplest to more involved, that resolve the vast majority of installation errors.

Before You Start: Check the Basics

Windows 11 has stricter hardware requirements than Windows 10, so a failed install often means your PC doesn’t meet them. Run Microsoft’s PC Health Check app (free from Microsoft’s website) to see which requirement is failing. Common culprits:

TPM 2.0 – often disabled in BIOS/UEFI; enable it under Security or Trusted Computing settings.
Secure Boot – must be enabled; look for it in Boot or Security sections of BIOS.
4 GB RAM and 64 GB storage – these are minimums; the installer will refuse to proceed if they’re not met.
Internet connection – Windows 11 Home requires an internet connection during setup; Pro can work around it but it’s easier to just connect.

If PC Health Check says everything is fine but the install still fails, move to the next fixes.

Free Up Disk Space

The Windows 11 installer needs about 20–25 GB of free space, but more is better. If you’re upgrading from Windows 10, the installer will also create a Windows.old folder that can take 10+ GB. To free space:

Open Settings > System > Storage and click Cleanup recommendations.
Delete temporary files, old Windows updates, and Recycle Bin contents.
Uninstall unused apps, especially large games or video files.
If you have less than 30 GB free, consider moving personal files to an external drive temporarily.

After freeing space, run the installer again. This fixes a surprising number of failures that show no clear error code.

Disable or Unplug Peripherals

External devices can interfere with installation, especially USB drives, external hard drives, and some printers or webcams. Unplug everything except your mouse, keyboard, and monitor. If you’re installing from a USB drive, keep that plugged in, but remove any other USB storage. Also disable Bluetooth and remove any SD cards. This is a quick, easy step that often resolves unexpected errors during the copy or reboot phase.

Run Windows Update Troubleshooter

If you’re upgrading via Windows Update and it fails, the built-in troubleshooter can fix common update issues:

Go to Settings > System > Troubleshoot > Other troubleshooters.
Click Run next to Windows Update.
Follow the prompts; it may clear the update cache or reset Windows Update components.

After it finishes, try the installation again. If it still fails, you can also manually reset the Windows Update cache by stopping the Windows Update service, deleting the contents of C:\Windows\SoftwareDistribution\Download, and restarting the service. This is safe and doesn’t affect your files.

Use the Media Creation Tool or ISO

If Windows Update keeps failing, download the Media Creation Tool from Microsoft’s official site. This tool lets you create a bootable USB drive or download an ISO file. Using it to upgrade your PC (run the tool and choose “Upgrade this PC now”) often bypasses the glitchy Windows Update path. If you prefer a clean install, you can boot from the USB and choose “Custom install”—but that erases everything, so back up first.

Another option: download the ISO, mount it by right-clicking and selecting Mount, then run setup.exe inside. This sometimes works when the Media Creation Tool doesn’t, and it keeps your files and apps.

Disable Third-Party Antivirus Temporarily

Third-party antivirus software (like Norton, McAfee, or Bitdefender) can block the installer from modifying system files. Temporarily disable real-time protection, or uninstall the antivirus completely before upgrading. You can reinstall it after Windows 11 is up and running. Windows Defender will keep you protected during the process. If you’re not sure how to disable it, check the antivirus’s settings or its vendor’s support page—most have a “pause protection” option that lasts a few minutes.

Check for Corrupted System Files

Corrupted system files on your current Windows 10 can cause the upgrade to fail. Run the System File Checker and DISM tools:

Open Command Prompt as administrator (search “cmd”, right-click, “Run as administrator”).
Type sfc /scannow and press Enter. Wait for it to finish.
Then type DISM /Online /Cleanup-Image /RestoreHealth and press Enter. This may take 15–30 minutes.
Restart your PC and try the installation again.

These commands repair Windows system files and restore the health of the system image. They don’t touch your personal files.

Reset Windows Update Components Manually

If the troubleshooter didn’t work, you can reset Windows Update components manually. This is a bit more technical but is a known fix for persistent update failures. Open Command Prompt as administrator and run these commands one by one:

net stop wuauserv – stops the Windows Update service.
net stop cryptSvc – stops the cryptographic service.
net stop bits – stops the Background Intelligent Transfer Service.
ren C:\Windows\SoftwareDistribution SoftwareDistribution.old – renames the update cache folder.
ren C:\Windows\System32\catroot2 catroot2.old – renames the catalog folder.
net start wuauserv, net start cryptSvc, net start bits – restarts the services.

Then restart your PC and try the upgrade again. This clears out any corrupted update files that might be blocking the installation.

Frequently Asked Questions

Why does Windows 11 installation fail with “TPM 2.0 required”?

Your PC’s TPM (Trusted Platform Module) is either disabled in BIOS or not present. Restart your PC, enter BIOS/UEFI (usually by pressing Del, F2, or F12 during boot), find the TPM setting (often under Security or Trusted Computing), and enable it. If your PC is older than 2016, it may not have TPM 2.0 at all, and you’ll need to replace the motherboard or stick with Windows 10.

Can I install Windows 11 without TPM 2.0?

Microsoft officially requires TPM 2.0, but there are registry hacks that bypass the check. These are not recommended because they can lead to instability and lack of security updates. If you attempt it, you do so at your own risk. It’s safer to upgrade your hardware or continue using Windows 10, which is supported until October 2025.

Will my files be deleted if the installation fails?

No, a failed upgrade typically leaves your files intact. The installer rolls back to your previous Windows version if something goes wrong. However, it’s always wise to back up important data before any major OS update, just in case.

How much disk space do I really need for Windows 11?

Microsoft says 64 GB minimum, but you should have at least 30–40 GB free before upgrading. The installer needs room for temporary files and the Windows.old folder. If you’re low on space, use the Disk Cleanup tool to remove old updates and temporary files.

What if the installation gets stuck at a certain percentage?

If it’s stuck for more than 30 minutes, it may be hung. Wait at least an hour before giving up, as large updates can take a while. If it’s truly stuck, force a restart (hold the power button), then boot into Windows 10 and try again after running the DISM and SFC commands. Sometimes a simple restart fixes it.

Why does the installer say “This PC can’t run Windows 11”?

This message appears when your hardware doesn’t meet the minimum requirements. Run PC Health Check to see which requirement fails. The most common are TPM 2.0, Secure Boot, or CPU not on the supported list. If your CPU is on the list but TPM is off, enable it in BIOS. If your CPU is not supported, you’ll need a newer processor.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

More in this bed

The whole Tech How-To bed →