In the WMI Class win32_DiskDrive my boot drive sits at \\.\PHYSICALDRIVE0. My question is do only boot drives sit at this address? Or does it depend on where the device is plugged into the motherboard? I'm looking for something static for the boot drive in win32_DiskDrive, so I can grab just the boot drive serial number. E.g. "SELECT SerialNumber FROM Win32_DiskDrive WHERE \\.\PHYSICALDRIVE0" Regards, The Dev.