Update Windows Security signatures

Applies to: SecurityWindows 10

To update a signature in Windows Security (or Windows Defender Security Center in previous versions of Windows 10):

  • Select Start  > Settings  > Update & Security  > Windows Security > Virus & threat protection.
  • Select Check for updates (or Virus & threat protection updates in previous versions of Windows 10).
  • Under Threat definitions, select Check for updates.
  • If Windows Security finds a new signature, it will download and install it.
  • The update completes with the new signature. Keep these points in mind.

    • Note: that if you get an error message while trying to download or update a signature, you can wait for at least one hour and try again or update signatures manually.

    • Also, make sure the signature you want to download is 50 MB or larger to ensure you get the complete signature file.