USB 2 Question

Hello.

Every time I plug in a USB device I get a pop-up that tells me “This device can work faster, please click this balloon for a list of available ports” or words to that effect. “Suitable ports” appear in bold on the list and indeed there is one in bold…

The problem is that the list is useless: how can I tell which hole to plug the thing into? I am sure I have tried all of them!

Thanks in advance

Paul