### [Click here if you are looking for the latest patch files!](https://github.com/zeffy/kb4012218-19/releases)

---

### [Click here for a list of Windows updates supported by this patch](docs/Supported_Updates.md)

---

## Preface

After reading [this article on gHacks](https://www.ghacks.net/2017/03/22/kb4012218-kb4012219-windows-update-processor-generation-detection/), I was inspired to look into these new rollup updates that Microsoft released on March 16. Among other things, the changelog mentions the following:

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

This update marked the implementation of a [policy change](https://blogs.windows.com/windowsexperience/2016/01/15/windows-10-embracing-silicon-innovation/) 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. 

That is essentially a giant middle finger to anyone who dare not "upgrade" to the steaming pile of garbage known as Windows 10. Especially considering the extended support periods for Windows 7 and 8.1 still have a few years left, and will be ending in 2020 and 2024 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](/../../issues/7) and [this](https://answers.microsoft.com/en-us/windows/forum/windows8_1-update/amd-carrizo-ddr4-unsupported-hardware-message-on/f3fb2326-f413-41c9-a24b-7c14e6d51b0c?tab=question&status=AllReplies)).

## Bad Microsoft!

I started by downloading the update package for my system (in my case, it was `windows6.1-kb4012218-x64_590943c04550a47c1ed02d3a040d325456f03663.msu`)

I extracted it using the command line `expand` tool:

```bat
md "windows6.1-kb4012218-x64"
expand -f:* ".\windows6.1-kb4012218-x64_590943c04550a47c1ed02d3a040d325456f03663.msu" ".\windows6.1-kb4012218-x64"
cd ".\windows6.1-kb4012218-x64"
md "Windows6.1-KB4012218-x64"
expand -f:* ".\Windows6.1-KB4012218-x64.cab" ".\Windows6.1-KB4012218-x64"
```

Great, now there's thousands of files to sort through! Just kidding. Sort of. Maybe. :thinking:

I ended up using PowerShell to sort through and filter out all the binaries that weren't related to Windows Update, like so:

```powershell
Get-ChildItem -Filter "wu*" -Exclude "*.mui" -Recurse | ForEach-Object { $_.FullName }
```

That narrowed it down to 14 files, excellent!

Next, I started comparing these binaries with the ones already on my system with [BinDiff] and [Diaphora]. I eventually got to `wuaueng.dll`, which turned up quite a few interesting new functions:

EA | Name | Basicblock | Instructions | Edges 
-- | ---- | ---------- | ------------ | -----
`00000600001DCB9C` | ``CWUTelemetryDownloadCanceledEvent::FireAsimovEvent(void)`` | 36 | 446 | 53
`00000600001D8F98` | ``CWUTelemetryDownloadCanceledEvent::`scalar deleting destructor'(uint)`` | 3 | 15 | 3
`00000600001D8FD0` | ``CWUTelemetryDownloadEvent::CWUTelemetryDownloadEvent(void)`` | 1 | 58 | 0
`00000600001DAEDC` | ``CWUTelemetryDownloadEvent::Init(CReporter *,long,long,ushort const *,long,_GUID,_GUID,CReportingOptionalValues &,AsimovDataInAddition *)`` | 6 | 50 | 8
`00000600001DAFB8` | ``CWUTelemetryDownloadEvent::InitializeMemebersFromOptionalData(tagOptionalData *)`` | 27 | 91 | 40
`00000600001D9100` | ``CWUTelemetryDownloadEvent::~CWUTelemetryDownloadEvent(void)`` | 2 | 60 | 1
`00000600001DC2C4` | ``CWUTelemetryDownloadFailedEvent::FireAsimovEvent(void)`` | 36 | 446 | 53
`00000600001DB114` | ``CWUTelemetryDownloadStartedEvent::FireAsimovEvent(void)`` | 36 | 446 | 53
`00000600001DB9EC` | ``CWUTelemetryDownloadSucceededEvent::FireAsimovEvent(void)`` | 36 | 446 | 53
`00000600001D8C48` | ``CWUTelemetryEventFactory::FireTelemetryEvent(CReporter *,long,long,ushort const *,long,_GUID,_GUID,CReportingOptionalValues &,AsimovDataInAddition *)`` | 11 | 76 | 17
`00000600001D8574` | ``CWUTelemetryEventFactory::GetTelemetryEvent(CReporter *,long,long,ushort const *,long,_GUID,_GUID,CReportingOptionalValues &,AsimovDataInAddition *,CWUTelemetryEvent * *)`` | 77 | 395 | 127
`00000600001DEE7C` | ``CWUTelemetryInstallCanceledEvent::FireAsimovEvent(void)`` | 34 | 409 | 50
`00000600001D8DD4` | ``CWUTelemetryInstallEvent::CWUTelemetryInstallEvent(void)`` | 1 | 57 | 0
`00000600001DD474` | ``CWUTelemetryInstallEvent::Init(CReporter *,long,long,ushort const *,long,_GUID,_GUID,CReportingOptionalValues &,AsimovDataInAddition *)`` | 6 | 50 | 8
`00000600001DD550` | ``CWUTelemetryInstallEvent::InitializeMemebersFromOptionalData(tagOptionalData *)`` | 23 | 81 | 34
`00000600001D8EFC` | ``CWUTelemetryInstallEvent::~CWUTelemetryInstallEvent(void)`` | 2 | 66 | 1
`00000600001DE67C` | ``CWUTelemetryInstallFailedEvent::FireAsimovEvent(void)`` | 34 | 409 | 50
`00000600001DF67C` | ``CWUTelemetryInstallRebootPendingEvent::FireAsimovEvent(void)`` | 34 | 409 | 50
`00000600001D8D9C` | ``CWUTelemetryInstallRebootPendingEvent::`scalar deleting destructor'(uint)`` | 3 | 15 | 3
`00000600001DD67C` | ``CWUTelemetryInstallStartedEvent::FireAsimovEvent(void)`` | 34 | 409 | 50
`00000600001DDE7C` | ``CWUTelemetryInstallSucceededEvent::FireAsimovEvent(void)`` | 34 | 409 | 50
`00000600001CAE68` | ``CWUTelemetryScanFailedEvent::FireAsimovEvent(void)`` | 31 | 416 | 46
`00000600001CA100` | ``CWUTelemetryScanRetryEvent::FireAsimovEvent(void)`` | 9 | 108 | 13
`00000600001CA588` | ``CWUTelemetryScanSucceededEvent::FireAsimovEvent(void)`` | 47 | 459 | 73
`00000600001CB790` | ``CWUTelemetryUnsupportedSystemClickSupportEvent::FireAsimovEvent(void)`` | 5 | 22 | 7
`00000600001CB9B0` | ``CWUTelemetryUnsupportedSystemClickSupportEvent::`scalar deleting destructor'(uint)`` | 3 | 17 | 3
`00000600001CB7FC` | ``CWUTelemetryUnsupportedSystemDetectionEvent::FireAsimovEvent(void)`` | 5 | 22 | 7
`00000600001CB970` | ``CWUTelemetryUnsupportedSystemDetectionEvent::`scalar deleting destructor'(uint)`` | 3 | 17 | 3
`00000600001CB724` | ``CWUTelemetryUnsupportedSystemNotificationDismissEvent::FireAsimovEvent(void)`` | 5 | 22 | 7
`00000600001CB9F0` | ``CWUTelemetryUnsupportedSystemNotificationDismissEvent::`scalar deleting destructor'(uint)`` | 3 | 17 | 3
`00000600001CB6B8` | ``CWUTelemetryUnsupportedSystemNotificationShowEvent::FireAsimovEvent(void)`` | 5 | 22 | 7
`00000600001CBA30` | ``CWUTelemetryUnsupportedSystemNotificationShowEvent::`scalar deleting destructor'(uint)`` | 3 | 17 | 3
**`0000060000102F08`** | **``IsCPUSupported(void)``** | **20** | **157** | **31**
**`00000600000AF3C0`** | **``IsDeviceServiceable(void)``** | **7** | **31** | **8**
`00000600000832CC` | ``TraceLoggingEnableForTelemetry(_TlgProvider_t const *)`` | 16 | 86 | 23
`0000060000083210` | ``TraceLoggingSetInformation(_TlgProvider_t const *,_EVENT_INFO_CLASS,void *,ulong)`` | 6 | 50 | 8

We have found culprits, [`IsDeviceServiceable(void)`](https://gist.github.com/zeffy/e5ec266952932bc905eb0cbc6ed72185) and [`IsCPUSupported(void)`](https://gist.github.com/zeffy/1a8f8984d2bec97ae24af63a76278694)!

## Solutions

Luckily, there are a couple of different ways to kill this CPU check by patching `wuaueng.dll`.

1. Change the value of `dword_600002EE948` (see [this line](https://gist.github.com/zeffy/e5ec266952932bc905eb0cbc6ed72185#file-isdeviceserviceable-c-L7)) which is at file offset `0x26C948`, from `0x01` to `0x00`. This makes `IsDeviceServiceable(void)` skip over the entire CPU check and immediately return the value stored at `dword_600002EE94C`, which by default is 1 (supported CPU). This is my preferred method, as it is a simple 1-byte change. **Note: this offset is only for the KB4012218-x64, for a list of all the patch offsets [click here](docs/Patch_Offsets.md).**

2. Fill all the instructions highlighted [here](https://gist.github.com/zeffy/e5ec266952932bc905eb0cbc6ed72185#file-isdeviceserviceable-asm-L24-L26) in `IsDeviceServiceable(void)` with `nop`s. This will enabling using the `ForceUnsupportedCPU` value of type `REG_DWORD` under the registry key `HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Test\Scan` (you will most likely have to create this registry key). You can set this value to `0x00000001` to force unsupported CPUs, or to `0x00000000` to use the default behaviour. You will probably need to restart your PC or restart the `wuauserv` service in order for changes to apply. **This is an internal testing feature used by Microsoft and could be removed in future updates, so I will not be providing xdelta files for it.**

## Caveats

- You have to apply a new patch whenever `wuaueng.dll` gets updated.
- SFC scan errors will most likely occur as it will believe the integrity of the system has been compromised.

[BinDiff]: https://www.zynamics.com/software.html
[Diaphora]: http://diaphora.re