When I used to reinstall XP, I'd use the last, free windriversbackup (1.09) to grab drivers. It still works on newer versions of Windows.
RE: pointing device manager to a folder. Sometimes you have to actually drill down into sub-folders in order to get a driver to load. Even when you have the "include sub-folders" ticked.
On OEM's, there's usually a folder of drivers, ie: Toshiba laptops & their "TOSAPINS" folder located on the C: drive. Have a poke around if you're reinstalling OEM & can reach a useable desktop- you may already have them there.
Lastly, always run Belarc or some sys info program, before you format, which will tell you what you're looking for. Even Dell, which supposedly offers a unique service tag, will offer up multiple wi-fi drivers for your model...