Microsoft Security Essentials includes a command-line utility which can be used to update the virus/malware definitions, initiate a scan, undo a recent definition update and perform other tasks. To know how to use the command-line utility, open a Command Prompt window (CMD.EXE) and execute the following command:
"%ProgramFiles%\Microsoft Security Essentials\MpCmdRun.exe" /?
| Command |
Description |
| -? / -h |
Displays all available options for this tool. |
| -Trace [-Grouping #] [-Level #] |
Starts diagnostic tracing |
| -RemoveDefinitions [-All] |
Restores the installed signature definitions to a previous backup copy or to the original default set of signatures |
| -RestoreDefaults |
Resets the registry values for Microsoft Antimalware Service settings to known good defaults |
| -SignatureUpdate [-UNC] |
Checks for new definition updates |
| -Scan [-ScanType] |
Scans for malicious software |
| -Restore -Name <name> [-All] |
Restore the most recently or all quarantined item(s) based on name |
| -GetFiles |
Collects support information |
In addition to the above information, detailed information for each command-line parameter is shown when you run the above command.
To update the MSE virus/malware definitions, use this command:
"%ProgramFiles%\Microsoft Security Essentials\MpCmdRun.exe" -SignatureUpdate
The command-line tool can be useful if you want to update MSE using Batch file, Script or using Task Scheduler.