A driver can be outdated for several reasons:
1. It's updated to support newer versions of Windows [that you don't have]
2. It's updated to support newer hardware [that you don't have]
2. It's updated to remove errors [that you don't have]
3. It's updated to offer new functions. [that you don't miss at them moment]
As long as it works for you, there is no need to update it. So there is no need for a program like Slimware either. And certainly not if you have to pay for it. I'd uninstall it, or - at most - run it once a year manually to see what it advises, most certainly not automatically for its real-time functions and lovely popups. And then maybe - after a good backup - update manually.
By the way, this is the editors 3.5 star review from http://download.cnet.com/SlimDrivers-Free/3000-18513_4-75279940.html#editorsreview :
"SlimDrivers scans for available updates for all of your drivers, and then manages the download and installation process for you. Rather than having to figure out which programs might be out of date and then checking for updates individually, you can use this program to significantly streamline the process and keep all programs running smoothly."
I' ve yet to see a driver change making any program running more smoothly than it did with the old driver, with the possible exceptions of the video driver in case of complex games.