Themken: there will very likely be full driver support missing with an upgrade no matter which modern OS you would choose.
sunshinecorp: Not with Linux, unless he has some very obscure win-only soundcard or something. And then he could probably find a post on some forum somewhere on how to roll his own driver for it.
Really now? Well let me tell you, I am on some limited drivers on my laptop for the graphics card meaning anything more complicated asked of it is handled by the CPU instead. Of course, anything is better than staying with Windows XP if I want to use it online.
My first hands on experience with Linux was having to "roll my own" (make it work on a newer OS than it was ever made for) driver for a printer, I failed. Of course, on Windows I would never even attempt to do that.
The OP could by all means try a live dvd/usb-stick of some suitable Linux distro to see how it works.