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Update: As of October 1, 2024, Microsoft has made it more difficult to bypass these compatibility checks -- but there is a workaround. For details, see this article. 

"Holy moly, it worked!"

That was the reaction of a reader who successfully upgraded a 12-year-old PC from Windows 10 to Windows 11 after being repeatedly blocked by the compatibility checker in Microsoft's Windows 11 Setup program.

Also: What is a TPM, and why does Windows 11 require one?

He had followed the advice in my recent article, "How to upgrade your 'incompatible' Windows 10 PC to Windows 11," and we'd exchanged several emails over a few days as he tried to figure out why it wasn't working. After getting over the final hurdle, he concluded, "We saved another laptop from the scrap pile."

Within the first week after I posted that article, two dozen people responded to my request for reports of their upgrade experience with similar reactions. Remarkably, every one of those correspondents was able to complete the upgrade, with those successes including at least two machines that were 15 years old. In the month after that, I heard from hundreds of people, with virtually all of them reporting success.

The results were enlightening, and thanks to those reports I've been able to formulate some guidelines to follow when deciding the best way to complete a Windows 11 upgrade. That's especially important with the end-of-support date for Windows 10 arriving in October 2025.

Also: Microsoft has a big Windows 10 problem, and only one year to solve it

There are two options available for upgrading to Windows 11 on a PC that doesn't satisfy the operating system's compatibility requirements. One is fully documented by Microsoft but still requires PCs to pass a lower compatibility threshold. The other is an undocumented hack that bypasses Microsoft's compatibility checker completely.

So, which one should you choose? That depends on which issues are preventing your PC from upgrading.

What's blocking your upgrade?

The published system requirements for Windows 11 are as follows:

• Processor: 1GHz or faster with two or more cores on a compatible 64-bit processor or system on a chip (SoC)
• RAM: at least 4GB
• Storage: at least 64GB of available storage
• Security: TPM version 2.0, UEFI firmware, Secure Boot capable
• Graphics card: Compatible with DirectX 12 or later, with a WDDM 2.0 driver
• Display: High-definition (720p) display, 9-inch or greater monitor, 8-bits per color channel

Some of those requirements are easy to meet. I doubt anyone will try upgrading a PC with less than 4 GB of memory, 64 GB of main storage, and a single-core CPU. If you have a PC with those specs, it's probably close to 20 years old, and it's time to retire it.

Also: How to set up God Mode in Windows 11 (and why you should)

The areas where an older PC is most likely to stumble are the CPU and security requirements.

• Incompatible CPU: The official upgrade requirements block upgrades on systems with CPUs that aren't on this official list. That rules out PCs built using most Intel Core processors earlier than 8th Generation (Coffee Lake, late 2017) as well as AMD Zen 1 processors.
• TPM 2.0 supported and enabled: Most PCs designed for Windows 10 include a firmware-based TPM. Some PCs from 2015 and earlier, typically business-class models, might include a TPM 1.2 as a separate component. (For more details on what this component does, see "What is a TPM, and why does Windows 11 require one?")
• Secure Boot supported: This is one of the more confusing requirements. The Secure Boot feature doesn't have to be enabled, it just has to be supported, and that means that the system has to be configured to use the Unified Extensible Firmware Interface (UEFI). If your system uses a Legacy BIOS, it will fail this test.

The easiest way to determine whether you'll be able to complete a simple Windows 11 upgrade is to run the PC Health Check utility, shown here.

Click the "Check now" button to see which compatibility issues are blocking your Windows 11 upgrade. 

Screenshot by Ed Bott

Grab the download from https://aka.ms/GetPCHealthCheckApp and install it. Then run the app and click the "Check now" button under the "Introducing Windows 11" heading. That action returns a list that shows you any areas where your system doesn't meet the full Windows 11 compatibility requirements.

Because this PC doesn't have a TPM, you'll need to use an unsupported hack to complete the upgrade.

Screenshot by Ed Bott

To check your Secure Boot status, use Microsoft's System Information utility, Msinfo32.exe. On the main page, labeled System Summary, look for the entries labeled BIOS Mode and Secure Boot State. This system (a virtual machine I created using a Legacy BIOS) is ineligible for a Windows 11 upgrade.

If you see these two entries in System Information, you'll be blocked from a normal upgrade to Windows 11.

Screenshot by Ed Bott

Armed with that information, you can now choose your upgrade strategy.

Which upgrade option should you choose?

As I mentioned earlier, you have two options for upgrading a Windows 10 PC that fails Microsoft's compatibility tests. I document both of those options in "How to upgrade your 'incompatible' Windows 10 PC to Windows 11,"

Option 1: A simple registry edit

Microsoft's documented (but unsupported) option is effective for PCs that were originally designed for Windows 10 and have no compatibility issues other than the CPU being too old.

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

To enable that upgrade, you make a single change to the Windows registry that tells the Windows Setup program to ignore the CPU check and to allow an upgrade as long as any TPM is present.

• If the PC Health Check app says your PC has an incompatible CPU, but it passes every other test, including the presence of a TPM 2.0 module, this option is for you.
• You can also choose this upgrade technique if you have an older PC with a TPM 1.2 chip installed and enabled.
• In some cases, you might need to go into your PC's firmware settings and enable the TPM to continue.

Seven of the people who reported on their Windows 11 upgrade experience said this option worked for them. "Went without a hitch," one reader said, echoing the consensus. Another person reported that he had just purchased a Dell OptiPlex PC with a 7th Generation Intel Core i7 with 32 GB of RAM fromAmazon Renewed . The upgrade "worked beautifully," he said in an email.

Also: Want to keep getting Windows 10 updates next year? Here's what it will cost

Two correspondents cautioned that the upgrade took several hours longer than they expected. Your total time will vary depending on your hardware, free disk space, and internet connection speed.

And don't be surprised if there's a lengthy pause when Windows Setup begins gathering updates and hits the 46% mark. That's normal. Resist the urge to cancel and start over.

Option 2: Bypass all compatibility checks

Most PCs designed in 2015 or earlier will be unable to take advantage of the simple registry edit to complete the upgrade. That's because they typically have no TPM or are configured with a Legacy BIOS rather than UEFI and thus don't support Secure Boot.

That was the case with roughly half the people who sent in upgrade reports. The most common configurations were PCs running 3rd- or 4th-generation Intel Core CPUs. In every one of those cases, poking around in firmware settings confirmed that there was no TPM option.

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

If you find yourself in that situation, there's an unsupported hack that allows you to run Windows 11 Setup and bypass all compatibility checks. If you're sufficiently technically advanced, you can do this yourself by copying the Windows 11 installation files from the ISO download to a local folder and replacing the Appraiserres.dll file in the Sources subfolder with a 0-byte file using the same name.

If that last paragraph reads like complete gibberish, there's an easier way. Use a free, open-source utility such as Rufus, which is available as a direct download or from the Microsoft Store. (Another option, Ventoy, is more challenging to use but might be appealing to people with a highly technical background.)

You can find full instructions for using Rufus to enable a Windows 11 upgrade in my post, "How to upgrade your 'incompatible' Windows 10 PC to Windows 11," Be sure to choose the option to customize the Windows installation and remove those pesky compatibility restrictions, as shown here.

This option isn't magic. It simply adds a required zero-byte file to the Windows 11 installation drive to bypass compatibility checks.

Screenshot by Ed Bott

Unfortunately, in October 2024, Microsoft implemented a change to its compatibility checker that makes this option more difficult to employ. After creating the necessary installation files, you need to open an elevated Command Prompt and issue a series of five commands. Rather than repeat those instructions here, I refer you to "How to upgrade your 'incompatible' Windows 10 PC to Windows 11," All the details you need are in the section headed "Option 2."

The most common complaint among readers who used this method is that it took longer than they expected. "Sure took its time!" one person noted. That might have more to do with the capability of the older hardware than with the upgrade method. As with the other upgrade technique, several people reported that the installation appeared to hang at 46% but eventually continued after the download of required updates was complete.

Also: The best Windows laptop you can buy

Overall, this technique got high marks. One person wrote, "As a novice, I found the Rufus route to be simple and painless."

If you want to add your report, or if you've tried either approach and have run into issues, send an email to Win11Upgrade [at] realworldwindows.com. I can't promise a reply, but I'm checking every message sent to this special inbox.

This article was originally published on September 10, 2024, and last updated October 5, 2024. 

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