Learn about Windows PowerShell
Summary: Use Windows PowerShell cmdlets in Windows 8.1 to update the antivirus definitions.
How can I use Windows PowerShell, rather than navigating the GUI, to force updates for Windows Defender?
In Windows 8.1, you can execute the following cmdlet and bring the Windows Defender up to date:
Hey Sean, thank you for sharing this tip. I had completely forgotten about this cmdlet.