You can install Windows 11 on a PC that fails the TPM 2.0, Secure Boot or processor checks, but it isn’t supported by Microsoft. The most reliable way is a clean install from a USB drive made with Rufus, ticking Remove requirement for 4GB+ RAM, Secure Boot and TPM 2.0. To upgrade in place and keep your files, PCs with at least TPM 1.2 can use a registry setting before running Setup. Before you do either, know the trade-offs: Microsoft doesn’t guarantee updates for unsupported PCs, and processors older than about 2008 can’t run Windows 11 version 24H2 or later at all.
Applies to: Windows 11 version 25H2 on PCs currently running Windows 10 or an older Windows 11 version. Last reviewed October 8, 2026. Microsoft can block these methods in future releases.
Step 1: Check what’s actually unsupported
Run the PC Health Check app, or look in Settings > Update & Security > Windows Update. Sometimes the only problem is that TPM or Secure Boot is turned off in the BIOS, which is easy to fix and makes the PC fully supported. See how to check and enable TPM and how to turn on Secure Boot.
Step 2: Understand the risks
- Updates: Microsoft says unsupported PCs aren’t entitled to updates. In practice many still receive them, but that can change.
- Notices: Windows may show a “System requirements not met” message in Settings or on the desktop.
- Old CPUs: Windows 11 24H2 and later need the POPCNT instruction. Processors from before roughly 2008 can’t boot it.
- Drivers: older hardware may lack Windows 11 drivers.
Method 1: Clean install with Rufus (most reliable)
- Back up everything; a clean install erases the drive.
- Download the Windows 11 ISO from Microsoft’s download page.
- Download Rufus from its official site and insert a USB drive of at least 8 GB.
- In Rufus, select the USB drive and the ISO, then select Start.
- In the Windows User Experience box, tick Remove requirement for 4GB+ RAM, Secure Boot and TPM 2.0. Tick other options if you want, such as removing the online account requirement. Select OK.
- Boot the PC from the USB and install Windows 11 as usual.
Full walkthrough: how to use Rufus to install Windows 11.
Method 2: Upgrade in place with a registry setting (TPM 1.2 PCs)
- Back up your files.
- Press Windows + R, type regedit, and go to HKEY_LOCAL_MACHINE\SYSTEM\Setup\MoSetup (create the MoSetup key if it’s missing).
- Create a DWORD (32-bit) Value named AllowUpgradesWithUnsupportedTPMOrCPU and set it to 1.
- Download the Windows 11 ISO, right-click it and choose Mount, then run setup.exe.
- Choose Keep personal files and apps and continue.
This needs at least TPM 1.2 and works best with Secure Boot on. If Setup still refuses, use Method 1.
After installing
- Run Windows Update and install any drivers your PC maker offers.
- Your existing Windows 10 license normally activates Windows 11 automatically.
- Keep backups, since future updates might not install on unsupported hardware.
Alternatives worth considering
- Stay on Windows 10 short term. Consumer Extended Security Updates end on October 12, 2027, so this buys you about a year.
- Buy a supported PC; see how to install Windows 11 on a new PC.
- For a supported PC, use the normal path: how to upgrade Windows 10 to Windows 11.
Frequently asked questions
Is this legal?
Yes. Bypassing the check isn’t illegal; you still need a valid license.
Can I go back to Windows 10?
Within 10 days of an in-place upgrade, use Settings > System > Recovery > Go back. After a clean install, you’d need to reinstall Windows 10 from scratch.
Matt Jacobs has been working as an IT consultant for small businesses since receiving his Master’s degree in 2003. While he still does some consulting work, his primary focus now is on creating technology support content for SupportYourTech.com.
His work can be found on many websites and focuses on topics such as Microsoft Office, Apple devices, Android devices, Photoshop, and more.