http://winsupersite.com/windows-10/how-stop-windows-10-upgrade-downloading-your-system

Open up Windows Update and click on View update history.

Click on Installed Updates.

In the search box in the upper right corner type in kb3035583. If the update is on your system it will show up in the results.

Click on the KB3035583 entry in the search results and you will be asked if you are sure you want to uninstall it. Click Yes to remove it.

The system may need to be restarted to complete the removal.

If you do not want to see the update any more be sure to hide it by right clicking on the KB3035583 listing in Windows Update and selecting Hide this update.

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there's also another way. You can block the icon from showing and disable notifications. Using the Windows registry editor, do this:

1. Navigate to: HKEY_LOCAL_MACHINE \SOFTWARE\Policies\Microsoft\Windows\Gwx

2. Create a new REG_DWORD registry value called: DisableGwx

3. Give it a value of: 1