How to Install Windows 11 on an Old PC (With or Without TPM 2.0)
Official Windows 11 Requirements
- CPU: 64-bit processor, 1 GHz or faster, 2 or more cores (official list at microsoft.com)
- RAM: 4 GB minimum
- Storage: 64 GB minimum
- TPM: version 2.0
- Secure Boot: UEFI compatible
- DirectX: 12 or higher with WDDM 2.0 driver
- Display: 720p, 9 inches or larger
Most PCs made before 2017 don’t have TPM 2.0, which prevents installation with the standard method.
Check Compatibility with PC Health Check
Download PC Health Check from Microsoft and run it. It will tell you exactly which requirements your PC doesn’t meet. If the only problem is TPM 2.0, you have options. If the CPU is too old, options are more limited.
Enable TPM 2.0 in BIOS (Official Solution)
- Restart and enter BIOS (F2, F10, Del key at boot, depending on manufacturer)
- Look for Security β TPM Device or Advanced β PTT (Intel) or fTPM (AMD)
- Enable it and save changes (F10)
- Restart and run PC Health Check again
Intel calls its firmware TPM implementation PTT. AMD calls it fTPM. Both are equivalent to TPM 2.0.
TPM 2.0 Bypass: Installing on Incompatible PCs
If your CPU is compatible but you have no TPM 2.0 at all, you can use the registry bypass. Boot from the Windows 11 USB, press Shift + F10 to open CMD, and run:
reg add HKLM\SYSTEM\Setup\MoSetup /v AllowUpgradesWithUnsupportedTPMOrCPU /t REG_DWORD /d 1 /f
Then return to the installer and continue. This installs Windows 11 with a warning that the PC isn’t officially compatible.
Will I receive security updates if I install Windows 11 on an incompatible PC?
Microsoft doesn’t guarantee updates on incompatible PCs. In practice, security updates have continued arriving, but this may change in the future.
Is it worth installing Windows 11 on a very old PC?
If the PC has a CPU older than 2013, performance will likely be poor. Consider whether Windows 10 (support until October 2025) or a lightweight Linux distribution isn’t a better option.
How do I create the Windows 11 installation USB?
Download the Media Creation Tool from microsoft.com, run it, choose ‘Create installation media’, select USB (minimum 8 GB) and wait. The tool automatically downloads and installs Windows 11 on the USB.
Conclusion
First check with PC Health Check. If only TPM is missing, enable it in BIOS (look for PTT or fTPM). If the PC is completely incompatible, the registry bypass allows installation, though without guaranteed future updates.
