When Microsoft announced that they would give Windows 10 as a free upgrade to all Windows users, it seemed like good news. Then they decided to force it on everyone by using Windows Update to push KB3035583 to everyone as an 'important' update. This installs a package called GWX (get Windows 10) that does some obvious things:-
* Displays a white Windows logo and many flags in the notification area.
* Brings up a dialog offering you Windows 10 every time you boot your PC.
* Background downloads the actual Windows 10 installation files to your C drive.
* Prompts you to run the install, reportedly with a dialog box that can't be closed.
GWX also engages in some borderline malware behaviour:-
* GWX is installed under an account that prevents even users with Administrator privs deleting it.
* It adds multiple tasks to the Task Scheduler that:
* Restart GWX.exe if it's stopped.
* Re-enable certain Windows Updates that you might have hidden.
* Resets the group profile setting that tells Windows not to offer new versions.
* These tasks cannot be removed via normal means.
* Using the Windows Update control panel to uninstall KB3035583 doesn't actually uninstall GWX.
So we want to remove GWX...
Step 1.
I googled for information on how to prevent Windows 10 from being installed. I came across the following article, which advises deleting the Windows 10 install files if they've already been downloaded, uninstalling KB3035583 and telling Windows Update not to install it again. However, as I mentioned above, this doesn't actually get rid of GWX from your PC and GWX itself will re-enable KB3035583 as if Microsoft doesn't trust you to use the function they provided for that specific purpose. But you should still follow these steps first.
Step 2.
This is where it gets ugly. To remove GWX, being Administrator isn't enough. You need to use your Administrator privs to take ownership of the folder containing GWX, then you will be able to remove it. Also you'll want to remove the scheduled tasks that it created to resist attempts at removal. You can't do these via the Task Scheduler user interface because they are owned by a Microsoft account "Trusted Installer". But since Task Scheduler stores its config in the registry, you can remove them with regedit.exe. The following blog post describes the steps required.
http://www.dedoimedo.com/computers/windows-7-to-10-gwx-how-to-remove.html
Step 3.
This is optional, but if you want to know at a glance if your system is free of GWX, there's a piece of freeware that monitors it for Microsoft shenanigans. If you don't want to install a piece of random software from the internet, fair enough, but I've had this running on my PC for months and the author seems legit.
http://ultimateoutsider.com/downloads/ (GWX Control Panel is on this page)
When your system is clean, it should look like this:- http://imgur.com/HLepi3s