How about the PNPDeviceID? *The example below only works with Fixed or Removable drives. CDrom and Network drives fail because of WMI calls. $drive = StringLeft(FileSelectFolder("Pick a Drive",""),2) $id = _GetPNPDeviceID($drive) msgbox(0,$id,"") Func _GetPNPDeviceID($drive,$fullid=0) $objWMIService = ObjGet("winmgmts:{impersonationLevel=Impersonate}!\\.\root\cimv2") If Not IsObj($objWMIService) Then Return -1 ;Failed to Connect to WMI on Local Machine $colDevice = $objWMIService.ExecQu