Installing PCI cards is simple as they just push in, all you will need is a screwdriver to secure the card to the case.
http://www.pcguide.com/byop/byop_Ins...nsionCards.htm
the above link should shows you how to do it with pictures [there installing a PCI modem]
As for your warrenty, i dont know... it depends on what the supplyer deems acceptable....
If something does go wrong.... put everything back the way it was, and keep quiet about what you did!
even better, if you het an engineer come to your house to fix the PC, make friends with him and ask for help putting in your new Sound card!
but dont worry, i doubt anything will go wrong... you'll be fine
