Does Windows Defender update if Windows Update is set to manual?

Solution 1:

Since Defender updates are delivered with Windows Updates, then just like other Windows Updates, if you have it set to Notify Only, it will wait until you OK it.

From the Windows 8 Help and Support regarding Defender:

To help keep your definitions up to date, Windows Defender works with Windows Update to automatically install new definitions as they're released. You can also have Windows Defender check online for updated definitions before scanning.

According to that, you can also have Defender do an (extra) check for definitions before starting a scan but. There is no UI control for that available, but you can easily modify how the scheduled scan is launched and with what options Windows Defender is working. The system calls MpCmdRun.exe, which has quite some command line flags. Here is how you modify it to update the signatures before the scheduled scan:

1. Open the Scheduled Tasks UI and search in the library for Microsoft\Windows Defender.

2. Change the command line flags (for the task MP Scheduled Scan) to:

   SignatureUpdate Scan -ScheduleJob -WinTask -RestrictPrivilegesScan

3. Done. Now Windows Defender will update it's signatures before it does a scan.

Solution 2:

Nope, Windows defender gets its virus signatures via Windows Update. If you read this Microsoft documentation you will see they make mention to updates taking place via WSUS (this is just a corporate front end for Windows Updates).

Solution 3:

I don't want Windows to update automatically, so I created an old time batch file to update Windows Defender, without updating Windows.

https://docs.google.com/open?id=0B_SFfC0m5rI0TE16NXB3a0doLVk (bat file)

You can put it in: C:\Users-your username-\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup Or just click to run it.