Struggled with this one for a while until I came across this fix…
This step will reset the permission settings on this system, which may take
us some time, your patience is highly appreciated.
1. Please click the link below and download the tool.
http://www.ecs-safe.com/Reset_subinacl.zip
Please Note: The third-party product discussed here is manufactured by a
company that is independent of Microsoft. We make no warranty, implied or
otherwise, regarding this product’s performance or reliability.
2. Save the file to your desktop.
3. Right click the Reset_subinacl.ZIP file and choose Extract
4. Follow the instructions and there will be two files (reset.cmd and
subinacl.exe)
5. Double click the reset.cmd file
6. You will see a DOS-like window processing.
(NOTE: It may take several minutes, please be patient. When it is finished,
you will be prompted that “Finished, press any key to continue”)
After completing the above steps, please refer to the Windows Update website
to install the WGA toll again. If it still cannot be installed, let’s move on
to the steps below to manually install it.
Step 2 Install the WGA engine manually
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1. Download the ActiveX cab file from the following link and then save it to
the Desktop.
http://download.microsoft.com/download/4/f/9/4f9730c0-2061-4028-bca9-…
Open the downloaded cab file and we will find the following two files:
LegitCheckControl.dll
LegitCheckControl.inf
2. Click “Start”, click “Run”, type: “%windir%\system32″ (without
quotations) and press Enter. Copy the LegitCheckControl.dll files into the
opened system32 folder.
3. Click “Start”, click “Run”, type: “REGSVR32 LegitCheckControl.dll”
(without the quotations) and press Enter. We will see a popup message stating
this process succeeded.
4. Click “Start”, click “Run”, type: “inf” (without quotations) and press
Enter. Copy the LegitCheckControl.inf file into the opened inf folder.
5. Right click on the copied LegitCheckControl.inf file in the inf folder,
and then choose Install. The WGA engine will be installed automatically.
After we finish the above steps, please restart the computer and try to
validate Windows again.