I have an older M-Audio Duo that I use for a power supply for a microphone. I recently purchased Sonar Home Studio and need the proper drivers and have only found PAY web sites with many drivers offered...any help would be appreciated.
 
Brent

Whenever asking about hardware the first thing you should list are some specs and Windows OS version.
The last Duo driver was made in 2003 and it's for Windows XP.
That interface is very old and not really worth the hassle it will create trying to get it to work.
You can however try using ASIO4ALL It might be your only option next to using WASAPI in Windows 10.
 
You can get your hands on a Focusrite solo for under a 100 bucks. Less hassle and very stable.
Only my opinion but I wouldn't waste my time looking for a driver for something that was made in the late 1990's/early 2000's. It would be the equivalent of looking to replace the gas tank on a 1975 Ford Pinto. More problems than its worth.

100% agree with what Chuck just said. 
For under $100 you can bring yourself into this century. 
And you are wise not to fall for the scam with the drivers sites,,, they always show at the top of a goggle search.
Only ever download directly from the manufacture, for anything.