Forget third party programs --usually they are the dreaded SNEAKWARE or SUCKERWARE--particularly things like DriverMax.
You get suckered into believing that these programs can actually find something -- and if they have it in their database (even though these drivers are public domain software) you will have to "pay a fee" to access that part of the site etc etc --seen it so many times before.
Just get the details of the sriver you can't find via Device manager --properties --driver details
You'll get something like PCI&VEN---- etc.
Copy and paste into a google search -- this should yield results of who the manaufacturere is -then go to the site. There are some data bases as well which contain a list of Vendor Id's too.
Here's a good start. (Article is quite old but still valid for the most part). How To Find Unknown Device Drivers By Their Vendor & Device ID