Windows 10 - Start > Settings (gear icon) > Update & Security
Updates install in the background automatically. You may be prompted to reboot.
Windows 7 - Start > Control Panel > Windows Update
Updates should automatically install every Sunday morning at 3:00am local time. You may be prompted to reboot. (If you miss the day/time window, it will try again 15 minutes after your next boot up.)
This is a healthy system
This system needs updates
If you receive this notice, after clicking "Check for updates", please email email@example.com ASAP!
This system needs repaired