How To Cancel Windows 10 Technical Preview Installation After Running WindowsTechnicalPreview.exe

The Windows 10 Technical Preview became available today for anyone who signs up for the free Windows Insider Program. With it, you can try out the new Start Menu and other features in the next version of Windows due out in late 2015. Unfortunately, the installer for the preview, WindowsTechnicalPreview.exe is a bit flawed. In this post, I'll point out the flaws and include instructions on how to cancel the installation once you've started it.

No Confirmations, Just Starts To Upgrade

Running WindowsTechnicalPreview.exe *immediately* starts the upgrade process without any confirmation, warning about what is going to happen, or opportunity to cancel. Once run, you'll see a small window with an indeterminate progress bar saying it is preparing to upgrade. There is no cancel button. After a few moments, it will show a 'Restart' button. Whether you click it or not, the damage has been done. An update has been installed that will cause Windows Update to show and automatically select an update to the Windows Technical Preview each time it is run. If you try to hide the update by selecting to Show Additional Updates and then right-clicking and selecting Hide, it will not hide the update. It will, however, corrupt the name of it so that it then only appears as "Windows Update".

Accidentally Running It or Assuming It's an ISO Download (It's Not)

If you ran it thinking it's an ISO downloader, you can be forgiven. That's what I did. The ISO download is hidden at the bottom of the download page under the title "Looking For ISO Files?". This section of the page is at the bottom and below the fold on even a higher resolution display. If you accidentally ran the EXE after downloading it and planning to move it to a virtual machine, sadly, the damage is still done.

Uninstalling the Update and Getting Windows Update Back to Normal

Since there's no confirmation and no way to avoid having the update show up selected every time you run Windows Update, getting the machine back to normal is important. This can be done by uninstalling the update that was applied by WindowsTechnicalPreview.exe. To do this:

  1. Open up Control Panel and select Programs and Features
  2. In the Programs and Features window, click on View installed Updates on the left-hand side
  3. Within this list, find the entry for KB2990214 or similar. It may be different based on build and Windows version and has been reported as 3050267 or 3050265 recently. If you sort by date, it should be the last thing installed. Sorting alphabetically helps as well. If sorted by category, it's within the Microsoft Windows section.
  4. Right-click the update and select Uninstall Update
  5. In the confirmation window, select Yes
  6. Windows will begin uninstalling and then prompt to restart. Select to restart. Note that at this point, there's a good chance it will get stuck applying the update on shutdown since the uninstaller appears to be buggy. Give it a good 15 minutes just to be sure before force restarting it.
  7. On restart, Windows will finish applying the update.
  8. Start up Windows Update to confirm that the prompt to upgrade to the Technical Preview is now gone. Note that if you had to forcibly reboot, Windows Update may take longer than normal as it will need to re-download the full update database. Additionally, any updates you may have previously selected to hide will be visible again.

Final Thoughts

The upgrade installer is poorly thought out and wasn't properly tested. As it is, it could almost be classified as malware as simply running it on a given PC and walking away can seriously damage the PC. Someone unfamiliar with the process could then allow it to upgrade without understanding what it meant and lose the ability to go back to their proper, stable operating system since the Windows 10 Technical Preview upgrade is irreversible. Hopefully Microsoft will push out a fixed installer soon.