4.3.2. Microsoft Security Essentials - Update

The Update tab is where you can manually update the virus & spyware definition files used by Microsoft Security Essentials.
You may need to do this if, for example, your computer has been switched off for some time and been unable to automatically download updates.

Simply click Update to start downloading updated definition files.

A progress bar proceeds as Microsoft Security Essentials searches for new spyware & definition files, downloads them as required and installs them.