Using the utility, which can be installed or used as a portable application, is about as easy as it gets—just click the Begin Scan button, wait a couple of seconds, and you will be shown a list of drivers that can be updated. The download button for each driver will take you to their web site, where you can download the drivers for free, without signing up for anything at all. Most of the drivers come with setup programs, but some of them are nothing more than zip files, and would need to be installed manually—hopefully something they can improve on in the future.
During our testing, we used the application on half a dozen PCs, and had varied results—on our XP test system, Device Doctor worked well and accurately found new drivers, but for Windows 7 we didn't have as much luck, with a few incorrect drivers being thrown at us. That said, Windows 7 was only released recently, so expect that support to improve in the future.
Device Doctor isn't perfect yet, but as a completely free, portable application that you can toss on your thumb drive, it's well worth a look. It might even save you some time searching for new drivers while you are fixing mom's PC.
Device Doctor is a free download for Windows only. Be sure to check out the full How-To Geek review for a more in-depth look, as well as instructions on installing drivers manually.