How to update Windows Defender
In order to detect malware, Windows Defender maintains a database of virus, spyware and other malware definitions. This definitions database must be regularly updated in order to detect new malware that has appeared recently. If it is not updated, your computer is not fully protected.
Updates are normally automatic and you do not have to worry about them. However, it is useful to check that they are taking place and have not become disabled for some reason (malware might try to do this).
1 Open Defender
So far we have only looked at the settings that turn features on and off in Windows Defender. The program itself is elsewhere. At the top of the settings is a button, Open Windows Defender. Click it to open the program.
2 Go to Update
When Windows Defender opens there are three tabs at the top. Click the Update tab.
3 Check and update
The date of the last update is displayed and it should be no more than a day or two old. It will often have today's date, which means it has the latest definitions and is providing the best security.
The Update definitions button can be used to manually update Windows Defender. It is useful to do this just before scanning the disk for malware because it then has all the latest malware definitions.
Course Contents: Windows 10 Security Guide