wufuc

Disables the "Unsupported Hardware" message in Windows Update, and allows you to continue installing updates on Windows 7 and 8.1 systems with Intel Kaby Lake, AMD Ryzen, or other unsupported processors.

Preface

The changelog for Windows updates KB4012218 and KB4012219 included the following:

Enabled detection of processor generation and hardware support when PC tries to scan or download updates through Windows Update.

These updates marked the implementation of a policy change they announced some time ago, where Microsoft stated that they would not be supporting Windows 7 or 8.1 on next-gen Intel, AMD and Qualcomm processors.

It was essentially a big middle finger to anyone who decides to not "upgrade" to the steaming pile of 💩 known as Windows 10. Especially considering the extended support periods for Windows 7 and 8.1 won't be ending until January 4, 2020 and January 10, 2023 respectively.

There have even been people with older Intel and AMD systems who have been locked out of Windows Update because of these updates (see #7 and this).

Bad Microsoft!

If you are interested, you can read my original write up on discovering the CPU check here.

Basically, inside a file called wuaueng.dll there are two functions: IsDeviceServiceable(void) and IsCPUSupported(void). IsDeviceServiceable(void) is essentially a wrapper around IsCPUSupported(void) that caches the result it recieves and recycles it on subsequent calls.

My patch takes advantage of this result caching behavior by setting the "hasn't run once" value to FALSE and the cached result to TRUE.

How it works

On system boot the wufuc scheduled task runs under the NT AUTHORITY\SYSTEM user.
wufuc determines what service host process the Windows Update service (wuauserv) runs in, and injects itself into it.
Once injected, it applies a hook to LoadLibraryEx that automatically patches wuaueng.dll when it is loaded.
Any previously loaded wuaueng.dll is also patched.

Several improvements over my script-based approach:

No system files are modified!
Heuristic-based patching, which means it will usually keep working even after updates.
C is best language.
No external dependencies except for Microsoft Visual C++ 2015 Redistributable.

How to install/uninstall?

Just download the latest release, and extract the wufuc folder to a permanent location (like C:\Program Files\wufuc) and then run install_wufuc.bat as administrator.

To uninstall run uninstall_wufuc.bat as administrator.

To temporarily disable the patch, just go to the Task Scheduler and disable the wufuc.{72EEE38B-9997-42BD-85D3-2DD96DA17307} task, then restart your computer.

How do I remove your old patch and use this instead?

I've included a utility script called repair_wuaueng.dll.bat that will initiate an sfc scan and revert any changes made to wuaueng.dll.

How to see wufuc's debugging message output?

You will need to download DebugView to do this.

The best way to get a log of the entire life-cycle of wufuc is to do the following:

Disable wufuc in Task Scheduler.
Restart your computer.
Start DebugView.exe as administrator and check Capture -> Capture Global Win32.
Enable wufuc in Task Scheduler.
Run wufuc in Task Scheduler.
Output will be shown in DebugView.