Operating under the premise that it is better to beg for forgiveness than to ask for permission, Microsoft for a long time bullied Windows 7 and Windows 8/8.1 users into upgrading to Windows 10 through the use the nag screens and other means. Microsoft was even so brazen as to download Windows 10 upgrade files on PCs without the owner’s permission,

Source: Hot Hardware – Microsoft Agrees To End Brazen Windows 10 Forced Upgrades That Incited Class Action Suit