With the recent release of Windows 8, many PC users are discovering that some of their older hardware is no longer functional. A quick review of Device Manager shows the notorious "!" next to the entry for the device. Although the built-in driver database for Windows 8 contains the needed files for most hardware, some more esoteric components don't have the needed files available.
The first resource to check would be the manufacturer's website, specifically the page for downloads or drivers. If a Windows 8 version isn't available, a Windows 7 equivalent may work. I've sometimes found even Vista drivers can be a useful substitute.
Of course, this may just be a temporary workaround until newer drivers are available so return to the website occasionally to check for updates.