There is a brilliant piece of software, which I was so impressed with I bought it, called Drivermax. It identifies and updates ALL drivers in your PC. Once update dit has an option to backup all your drivers to a folder on your hard disk.
It also has a facility which identifies 'Unknown Hardware'. It runs in free mode but I am not sure what the restrictions in functionality are in free mode. It is only around $20 to buy and I have used it on many PCs. I would be surprised if it couldn't solve your problem.