Update for Windows 7 and 8.1 silently installs Windows 10 downloader

Update for Windows 7 and 8.1 silently installs Windows 10 downloader

Microsoft has released an optional update that “enables additional capabilities for Windows Update notifications when new updates are available to the user”. We discovered the update is actually a downloader for Windows 10 which will notify the user that Microsoft’s upcoming operating system can be downloaded.


(Dutch version of Windows 8.1 – Windows 10 downloaden (download Windows 10) clear visible as file description)

Windows Update KB3035583 doesn’t reveal much about itself, only that it adds additional capabilities to Windows Update and applies to computers running Windows 8.1 or Windows 7 Service Pack 1. The update is offered as a recommended update since March 28th and because it’s a recommended update users have to  manually put a checkmark next to the update in order to receive it.

Once the update is downloaded it adds a folder to System32 called “GWX” which contains 9 files and a folder called “Download”. One of the four .EXE files reveals what the update really is, the description of GWXUXWorker.EXE states, “Download Windows 10”. This explains the X in the name, the X is the Roman number 10.

Update: Want to get rid of this KB3035583 – Windows 10 Downloader Update? Read on here

The folder also contains “config.xml” which contains some URLs that at the moment of writing didn’t work.  The config  file mentions “OnlineAdURL” that points to https://go.microsoft.com/fwlink/?LinkID=526874 and Telemetry BaseURL pointing to http://g.bing.com/GWX/.


The section “Phases” describes how the downloader should behave when the Windows 10 release date nears. Initially, during phase “None”, all features are disabled, then during  phase “AnticipationUX” advertising banners will be shown, presumably on a homescreen tile and additionally a tray icon will appear.

The next phase is called “Reservation” which according to the config file will show the advertisement tile, the tray icon but also a reservation page. Further phases are the first publication of the final RTM (release to manufacturing), version the general availability (GA) as well as various phases of the upgrade process such as UpgradeDownloadInProgress, UpgradeDownloaded, UpgradeReadyToInstall, UpgradeSetupCompatBlock, UpgradeSetupRolledBack and UpgradeSetupComplete.

It appears Microsoft is serious when it comes to upgrading Windows 7 and Windows 8.1 users to Windows 10. The upgrade will be free in the first year and it appears Microsoft will take that time to convince users to upgrade. Users that don’t want to receive the upgrade “advertisements” should simply not install the recommend update. If Microsoft however decides to make KB3035583 an important update it will install automatically with other Windows update.

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