As promised last October, Microsoft has gone through with reclassifying the Windows 10 upgrade as a "recommended" update on Windows Update for Windows 7 and 8.1 users



From Windows Central:

Now that the upgrade is classified as "recommended," some users who have automatic updates enabled may see the upgrade automatically begin installing. However, users can turn down the option to go through with the upgrade before it is installed. And if you find you accidentally upgraded to Windows 10 and didn't intend to, you have 31 days to roll back to your prior Windows 7 or 8.1 installation.

  Windows 10 is now a recommended update for Windows 7 and 8.1 users