Microsoft Security Essentials (MSE) updates its virus definitions using Windows Automatic Update. We can also use its built-in command "MpCmdRun" to download and install virus definition updates without Automatic Update.
But what to do in case you want to update MSE offline? Many times we don't have Internet connection in our systems, in this situation how would you update MSE so that it can detect and remove all known virus and spyware?
Here is the solution. You can download offline installers for all latest MSE virus definition updates using a system which have a working Internet connection and then you can run that offline installer in any other system to update MSE virus definitions.
Following are official download links to download MSE virus definition updates:
Once you download the file, run the file using Administrator privileges and it'll install all the latest virus definition updates required for MSE.