With the prospect of the full Windows 11 launch later in 2021, Windows users are attempting to figure out if their existing hardware will receive the free upgrade.

Microsoft's PC Health Check App is the official tool for checking your upgrade eligibility­, but frustratingly, it doesn't provide enough information about why your system is ineligible for the Windows 11 upgrade.

That's where the WhyNotWin11 app steps in, delivering much more information about your system's Windows 11 compatibility and where it might be falling short.

Check Your Windows 11 Upgrade Status with WhyNotWin11

Microsoft's PC Health Check app came in for some rightful criticism after the Windows 11 launch event. Microsoft's Windows 11 eligibility checking app first returned a series of incorrect compatibility checks, along with a message that said Yes or No (in so many words).

Related: When Can I Install Windows 11? Am I Eligible to Upgrade to Windows 11? Your Questions Answered.

Microsoft then released an update to the PC Health Check app that provided slightly more detail but still fell short of the expectations of Windows users. Adding insult to injury, Microsoft then pulled the PC Health Check app entirely due to the number of changes taking place in the background regarding CPU requirements, TPM eligibility, and more.

For now, you can try the open-source WhyNotWin11 app, which provides a much more detailed overlay of your Windows 11 system compatibility, delivering results "based upon currently known requirements."

The last sentence is a nod to the fact that Microsoft's Windows 11 launch hasn't been clear sailing. At least, not the hardware requirements side of things.

Back to the WhyNotWin11 app. Download the latest version of the app, then run it. The free eligibility checker doesn't require installation and runs straight from the executable. Once you run the checker, you'll see the detailed list of compatibility results, including Architecture, Boot Method, Secure Boot, and TPM Version.

Below, you can see the Windows 11 upgrade eligibility for my current desktop computer. Microsoft's PC Health Check app had already confirmed that it wasn't eligible for the free Windows 11 upgrade, but the WhyNotWin11 app explains why with a little more nuance.

whynotwin11 check upgrade

Microsoft Changing Windows 11 Hardware Specifications

WhyNotWin11 is a useful app, no doubt. However, the developer has acknowledged that they're only reacting to Microsoft's ever-changing specification updates. So while they'll keep the app updated as information arises, you'll also have to update the WhyNotWin11 app to account for any changes.

In that, there are undoubtedly more changes coming to the hardware specifications for Windows 11. So, even if your current hardware doesn't match the Windows 11 specifications now, it may do in the future. That said, Microsoft is unlikely to drop certain specifications too low, such as the CPU requirement remaining relatively high.