Click any INF file that displays in the file list and then click the Open button. The Update Driver Software wizard will read the information from all the INF files in this folder.
INF files are the only files that Device Manager accepts for driver setup information. So while you may know that a folder you've selected has all sorts of files in it, it's an INF file that the Update Driver Software wizard is looking for.
Couldn't find an INF file in the folder you selected from your driver download?
Try looking in another folder within the extracted drivers. Maybe you chose the wrong one.
Couldn't find an INF file in any folder from the extracted driver files?
The driver download may have been damaged or you may not have extracted them properly. Try downloading and extracting the drivers again. See Steps 1 and 2 again if you need help.