I've just gotten some information from our PCI-express support people that the way to determine is this:

- View devices by connection.

- For the device in question, look at its parent.

- If its parent says "Root Port" and/or "Express" somewhere in its name, it is almost definitely a PCI-express bus to which that device is connected. However, the name string is vendor-generated and comes from the vendor's driver, so it could say just about anything. Hopefully they all follow the convention and say approximately the right thing.

- If its parent says "PCI Standard PCI-to-PCI bridge", then it is a legacy PCI bridge, and definitely not a PCI-express bus. In this case, that particular name string is built into Windows and you can be fairly certain about it.

So there we go.