I used to use driver magician sometimes (when Win7 was installed). But its not free. But, it did find some drivers for whatever I had installed.).
Even if it found drivers (that weren't from the manufacturer's site, the drivers still worked, and they were more recent that the installed drivers)
And yup, normally with Windows (well what I usually do) is install it, and the 1st thing you should do is install chipset drivers (usually from Intel) if its an Intel based system. Then everything else
XP didnt have anything on the CD (like NIC drivers/wireless drivers). Unless you slipstreamed the drivers etc
Or, if you don't download the drivers before you reinstall XP, (obviously), you wont get online (unless you get the drivers with another computer), then install the drivers after
WIn8 wasn't too bad on this. I'm still using the windows sound/HDMI,NIC drivers at the mo. The only thing that wasn't compatible was the webcam (VX-3000). According to the Widows 8 compat site it's not compatible.
I may install the vidcard drivers now that there's WIn8 drivers for it. but its only got WDM 1.1 functionality or something. Which is what Win8 installed I think. So, I may not notice any diff.
I use a vidcard with HDMI on it, but it probably wont make the sound any better. I'm only using the monitor speakers. I dont have any speakers at the mo