Whether you wanted Windows 10 or not, the new operating system might already be on your PC. Windows 7 and 8.1 computers throughout the world are automatically downloading the files for upgrading to Windows 10.
Microsoft confirmed to The Register that people who haven't even signed up for downloading the new OS are still getting the files anyway:
For those who have chosen to receive automatic updates through Windows Update, we help customers prepare their devices for Windows 10 by downloading the files necessary for future installation. This results in a better upgrade experience and ensures the customer’s device has the latest software.
Windows Update, enabled by default, is used primarily to deliver patches that prevent potential security problems. Using this pipeline to push your new product on customers feels, well, wrong. These PC users don't have to install Windows 10 once the files are on their computer but the way Microsoft is going about this feels a bit shady.
What makes the hidden download more annoying is the size of Windows 10. The upgrade files are between 3.5 and 6 GB. Downloading them is especially inconvenient for people who have metered bandwidth or limited hard drive space.
If you want to stop this automatic download, the answer isn't to disable Windows Update. As previously stated, that feature provides a lot of useful patches for your system. Instead, there's a way to remove the Windows 10 files from your system (if they're already there) and block them from being re-downloaded. Here are the step-by-step instructions, courtesy of Ghacks:
Removing Windows 10 Upgrade Files
1. In the Start menu, search for "Programs and Features."
2. Click "View Installed Updates" on the left side of the window that pops up.
3. Windows 7 users should find updates called 3035583, 2952664, and 3021917. For Windows 8, these updates are called 3035583 and 2976978.
4. Right-click these updates and select "Uninstall." 5. Restart once you've done this for every update.
Blocking Windows 10 Upgrade Files
1. Search for "Windows Update" in the Start menu.
2. In the window that pops up, click "Check for Updates" on the left.
3. The list that pops up should include the Windows 10 updates listed in the "Removing Windows 10 Upgrade Files" steps above. Right-click each and select "Hide Update."
While some Windows users are hesitant to upgrade to Windows 10, either due to concern over its surveillance features or potential bugs, many have made the switch. Microsoft said that over 75 million devices were running Windows 10 by late August. Windows 10 is now one of the most-used operating systems on Steam as well.