Richard Siddaway's Blog

Reading mounted device information from the registry

Interesting question about reading the registry.  How do you read HKLM:\SYSTEM\MountedDevices and pull out the name of the device and the associated data.

Get-Item -Path HKLM:\SYSTEM\MountedDevices

returns data of this form

Name                           Property
----                           --------
MountedDevices                 \DosDevices\C: : {218, 187, 32, 142...}
                               \DosDevices\G: : {92, 0, 63, 0...}
                               \DosDevices\E: : {95, 0, 63, 0...}
                               \DosDevices\F: : {92, 0, 63, 0...}
                               \DosDevices\D: : {218, 187, 32, 142...}
                               \DosDevices\I: : {95, 0, 63, 0...}

We need to drill into the property but if we expand the property we will only get the name of the device. So we need to loop through those names

$data = @()            
Get-Item -Path HKLM:\SYSTEM\MountedDevices |            
select -ExpandProperty Property |            
where {$_ -like "\Dos*"} |             
foreach {            
 $name = $_            
$data += New-Object -TypeName psobject -Property @{            
  Device =  $name             
  Value  = (Get-ItemProperty -Path HKLM:\SYSTEM\MountedDevices -Name $name)."$name"            
 }            
            
}            
$data

To simplify the output is limited to Dos devices

Get-itemproperty returns the data with the name of the device as the property name so we need to drill in to get the value