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On October 14, 2025, Microsoft will stop delivering security updates to your Windows 10 PC unless you're willing to pay an exorbitant price to join the Extended Security Updates program. 

Also: Still have a Windows 10 PC? You have 5 options before support ends next year

If you try to upgrade to Windows 11 on a PC over a few years old, you'll be told, in no uncertain terms, that your old PC doesn't qualify, because its CPU isn't on the official list of compatible processors. Microsoft has made it abundantly clear that it will not revise those requirements. You will also hit roadblocks if your PC doesn't have a Trusted Platform Module (TPM) version 2.0.

While that might be the official policy, as with everything Windows-related, it pays to read the fine print.

Those pesky restrictions prevent you from automatically upgrading to Windows 11 using Windows Update or the Windows 11 Installation Assistant. Yet there are two fully supported workarounds, as I document in 's Windows 11 FAQ.

Also: How to install Windows 11 the way you want (and sneak by Microsoft's restrictions)

If you're willing to perform a clean installation of Windows 11, you can boot from installation media and run Windows Setup. That option skips the CPU compatibility check completely. After the installation completes, you'll need to reinstall all your apps, restore your data files, and tweak settings to personalize your system preferences.

Want to avoid all that hassle? Follow these four steps.

An important note:Your computer still needs to meet all the other requirements for Windows 11. It must be configured to start up using UEFI, not a legacy BIOS configuration.Secure Boot must be enabled.Also, you need to have a TPM enabled; version 1.2 is OK but a system without any TPM or with the TPM disabled will fail.

If you're not sure about your system configuration, run the System Information utility, Msinfo32.exe, and look at the System Summary page. Pay special attention to the BIOS Mode value. If it says "Legacy," you'll need to reconfigure your system to UEFI mode (and reformat your system disk) before you can install Windows 11.

How to upgrade your old 'incompatible' PC to Windows 11

1. Change one key in the Windows registry

You need to make one small change to the Windows registry, as documented in this Microsoft support document. This change tells the Windows 11 Setup program to skip the check for compatible CPUs and to allow installation on a PC with an older TPM (version 1.2). The usual warnings apply when working with the registry, of course, and I recommend you make a complete backup before proceeding.

Open Registry Editor (Regedit.exe) and navigate to the following key:

HKEY_LOCAL_MACHINE\SYSTEM\Setup\MoSetup

If the MoSetup key, doesn't exist, you need to create it. Right-click the node for HKEY_LOCAL_MACHINE\SYSTEM\Setup in the left-hand navigation pane, then choose New > Key. Name it MoSetup and press Enter.

Also: Why 'debloating' Windows is a bad idea (and what to do instead)

Select the MoSetup key and then right-click in any empty space in the pane on the right. Choose the option to create a new DWORD value. (Don't choose the QWORD option!)

Replace the default name for that key by typing the text AllowUpgradesWithUnsupportedTPMOrCPU and then press Enter. Then double-click the new value and change the "Value data" box to 1. The result should look like this:

Use this registry tweak to override the Windows 11 CPU and TPM compatibility checks.

Screenshot by Ed Bott

Click OK to save your change, and then restart your PC.

2. Download the Windows 11 ISO

On the PC you want to upgrade, go to the Windows 11 Download page (aka.ms/DownloadWindows11) and choose the option at the bottom of the page, "Download Windows 11 Disk Image (ISO) for x64 devices." Save the ISO file in your Downloads folder.

Also: Wiping a Windows laptop? Here's the safest free way to erase your personal data

Note that this is a big file. Depending on the speed of your internet connection, the download could take a while.

3. Mount the ISO file in File Explorer

After the download completes, open File Explorer and double-click the ISO file. Doing so mounts the file as a virtual DVD drive in its own folder.

4. Run Windows Setup

In File Explorer, find the Setup.exe file and double-click it to begin the upgrade. You'll see a stern warning about compatibility issues, but after you click OK on that dialog box, your upgrade should proceed without any serious issues. You'll have three options: you can keep your apps, settings, and files (Full Upgrade); keep your data files but start fresh with apps and settings (Keep Data Only); or start completely fresh (Clean Install).

Also: The best Windows laptops you can buy: Expert tested and reviewed

If you want more control over the upgrade process and aren't afraid to mess with creating custom installation media, you can use the free, open-source utility Rufus. My colleague Lance Whitney has the full details in "How to install Windows 11 the way you want (and sneak by Microsoft's restrictions)."

If you've tried this upgrade, I want to hear about your experience. If it worked, please share the details. If you ran into snags, send me an email so we can figure out what's going wrong. Be sure to include details including the make and model of your PC and screenshots of any error messages. I've set up a special inbox just for this feedback: Win11Upgrade [at] realworldwindows.com.

This article was originally published on April 9, 2022, but has been updated multiple times since then. It was last updated August 17, 2024. 

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