Windows users have reported that their computers are upgrading to the free Windows 10 upgrade without there permission. So be careful if you don't want to use the free upgrade to Windows 10, because it can do it without your asking you to upgrade, you leave your computer on, come back and boom you have just upgraded to Windows 10 without asking for the upgrade. This has been causing a lot of problems for some computers and has even corrupt the install during the upgrade process.
Reddit has a post saying over 3000 comments from people complaining that the major update has been forced on them - Reddit thread
Microsoft pushes Windows 10 upgrade to PCs without user consent
Warning: Windows 10 May Auto-Install On Your PC
Microsoft reportedly installing Windows 10 without consent -- again
Fearing forced Windows 10 upgrades, users are disabling critical updates instead
NEVER 10
GWX CONTROL PANEL
Reddit has a post saying over 3000 comments from people complaining that the major update has been forced on them - Reddit thread
Microsoft pushes Windows 10 upgrade to PCs without user consent
Warning: Windows 10 May Auto-Install On Your PC
Microsoft reportedly installing Windows 10 without consent -- again
Fearing forced Windows 10 upgrades, users are disabling critical updates instead
NEVER 10
GWX CONTROL PANEL