Configure Windows Defender to Search for Viruses on Your Network Hard Drives

Windows Defender is the Microsoft antivirus that comes installed by default in Windows 10. Today, it is the best free antivirus that we can install on our computer, offering maximum protection and an almost negligible impact on computer performance. However, despite its proper functioning, this antivirus lacks some functions that many users may use. One of them is, for example, the possibility of analyzing network hard drives, mapped drives and even our NAS server (if we have one in our house).



When we look for viruses with Windows Defender, Microsoft’s antivirus analyzes without problem all the hard drives that we have connected to the computer, in addition to the memory and the running processes. However, if we have a hard disk connected in a network , either on a NAS, through the USB of our router or connected to another computer and mapped on ours, Windows Defender does not analyze it. Neither in the quick exam nor in the full exam.

Windows Defender - examen de seguridad

If we perform a personalized exam, then we can choose which units we want to analyze. And in that almost, if we choose to analyze a network drive, the antivirus will scan it without problem. However, personalized exams do not protect us from all threats, since they are not automatic.

Análisis personalizado Windows Defender

We do not know why Microsoft has not decided to enable this feature in its antivirus. Nor why it has not enabled an option that allows us to easily activate it if needed. However, if we want this antivirus to automatically scan the mapped drives on our computer, we can configure Windows Defender with this trick.

How to enable the analysis of mapped drives in Windows Defender

There are several ways to enable this hidden Windows Defender function so that the antivirus can analyze the mapped drives connected to the computer. We can do it from user policies, from the registry or with a simple PowerShell command.

Not to complicate it, we are going to use PowerShell. We use the Windows search engine to open a window of this terminal with administrator permissions and all we have to do in it is to run the following command:

Set-MpPreference -DisableScanningMappedNetworkDrivesForFullScan 0

Habilitar análisis de unidades mapeadas en Windows Defender

Ready. No need to restart or do anything else. Once the command has been executed, Windows Defender will start to include the mapped drives in the full system exam.

How to disable this feature

In the event that tomorrow we no longer want this antivirus to include these units, all we have to do is run another command in PowerShell (with administrator permissions):

Set-MpPreference -DisableScanningMappedNetworkDrivesForFullScan 1

This returns the antivirus to its original state.

Of course, we must bear in mind that if we configure Windows Defender to analyze the drives on a network, the process will take much longer, depending on the capacity of the drives. And even if we have it disabled, the antivirus will continue to scan all files equally when we open a network folder from the file browser.

So, if we have a malware or a potentially unwanted application, Windows Defender will end it. Even if it is hidden on a NAS or network hard drive.