Microsoft’s introduction of Windows 11 in 2021 brought with it a set of stringent hardware compatibility requirements that have since sparked considerable discussion among users and tech enthusiasts alike. The operating system’s upgrade process for Windows 10 PCs includes a compatibility appraiser that meticulously checks hardware specifications. If a user’s CPU is not on the approved list or if the machine lacks a Trusted Platform Module (TPM) version 2.0, the upgrade will not proceed.
Among the Windows community, this compatibility check was perceived more as a hurdle than an insurmountable obstacle. Many users quickly unearthed methods to bypass these restrictions, enabling upgrades on systems that technically did not meet the requirements. One widely shared technique, which I detailed in a popular article, allows users to modify the registry to facilitate the upgrade, albeit with the caveat that such installations remain unsupported. A crucial stipulation for this method is that the PC must have a TPM enabled, even if it is an older version 1.2. Without a TPM, the upgrade is simply not possible.
The second method, a more rudimentary yet effective hack, involves replacing the compatibility appraiser module (Appraiserres.dll) with a zero-byte file. This process can be effortlessly executed using the Rufus utility, which automates the modification with just a click. Remarkably, this approach has proven successful even on older PCs lacking TPM and Secure Boot capabilities.
Recent Developments in Upgrade Options
However, a recent update has introduced new challenges. With the rollout of Windows 11 version 24H2 on October 1, Microsoft appears to have altered certain settings, disrupting the second upgrade method. Reports have surfaced from users who attempted to upgrade using Rufus, only to encounter error messages signaling failure.
In my own testing, I replicated this issue on a virtual machine configured without a TPM and utilizing a Legacy BIOS. This setup, which does not meet the Secure Boot requirement, also resulted in an upgrade failure. Yet, in the ongoing cat-and-mouse dynamic between Microsoft and the Windows enthusiast community, this setback has been met with swift responses. Following a user report on GitHub, Rufus developer Pete Batard promptly provided a workaround.
For those attempting in-place upgrades, Batard outlined a series of commands to be executed from an elevated command prompt, which would adjust the registry settings prior to running the Setup.exe. These modifications were initially shared by the creators of the Win 11 Boot And Upgrade FiX KiT. Users are encouraged to copy these commands directly to ensure accuracy:
reg.exe delete "HKLMSOFTWAREMicrosoftWindows NTCurrentVersionAppCompatFlagsCompatMarkers" /f 2>NUL reg.exe delete "HKLMSOFTWAREMicrosoftWindows NTCurrentVersionAppCompatFlagsShared" /f 2>NUL reg.exe delete "HKLMSOFTWAREMicrosoftWindows NTCurrentVersionAppCompatFlagsTargetVersionUpgradeExperienceIndicators" /f 2>NUL reg.exe add "HKLMSOFTWAREMicrosoftWindows NTCurrentVersionAppCompatFlagsHwReqChk" /f /v HwReqChkVars /t REGMULTISZ /s , /d "SQSecureBootCapable=TRUE,SQSecureBootEnabled=TRUE,SQTpmVersion=2,SQRamMB=8192," reg.exe add "HKLMSYSTEMSetupMoSetup" /f /v AllowUpgradesWithUnsupportedTPMOrCPU /t REG_DWORD /d 1
After implementing these commands, I found that the upgrade proceeded smoothly. The next iteration of Rufus is expected to incorporate these adjustments into a batch script, allowing users to bypass the new restrictions more easily.
It appears that the documented upgrade method provided by Microsoft remains unchanged. For systems equipped with a TPM and configured with UEFI and Secure Boot, the upgrade process should be straightforward, regardless of CPU compatibility. Moreover, there seems to be no compatibility check for upgrades on machines already running Windows 11, ensuring those installations remain unaffected.
Nonetheless, the added compatibility checks for older hardware lacking a TPM or utilizing Legacy BIOS configurations present a significant usability challenge, particularly for users who may not possess extensive technical knowledge regarding Windows deployment. As I continue to explore these scenarios, I invite anyone experiencing upgrade issues to reach out with details, including their PC’s make and model, along with any error message screenshots. A dedicated inbox has been established for this feedback: Win11Upgrade [at] realworldwindows.com.
