If you have WScript installed and enabled, scrrun.dll:
[VBA]Sub ShowNetworkDrives()
Dim d As Object
Dim msg As String
Dim dDriveType As String

For Each d In CreateObject("Scripting.FileSystemObject").Drives
dDriveType = d.DriveType
'3=Newtwork Drive, 6=Network CDROM with CDFS file system
If d.IsReady = True And (dDriveType = 3 Or dDriveType = 6) Then
msg = msg & d.driveletter & vbNewLine
End If
Next
If msg = "" Then msg = "No network drive found."
MsgBox msg
End Sub[/VBA]