Issue with sound card and drivers in general

I bought a Creative 16 PCI sound card for my computer, and I have a question: I disabled the on-board AC '97 sound via Hardware management (XP) but is there any issue about the drivers for the AC '97 still being active, possibly degrading my system preformance? If so, how can I check/safely uninstall them to avoid conflict?

A last, slightly related topic: Should I download drivers from the respective company website, or if present, download the one that appears on windowupdate? Should I just use the driver that is most up-to-date?

 

control pannel/adminastrative tools/computer managment, then click on Device manager there you can simply disable or uninstall on board drivers!
As far as new drivers I would use the drivers from creative off thier web site.