LOL - you go for it.

For your sound card, right-click "My Computer" and select properties, then device manager (or hardware tab, then device manager if on XP).
You'll see a list of devices - near the bottom is Sound, video and game controllers - double click it. It should list the sound card type in there.
To the upgrade, it obviously depends how much disposable cash you've got, but if you're serious about getting a 9800 Pro, then you should consider this:
At the moment, there is no processor on the market that can keep up with the speed capablility of the 9700, never mind the 9800. That includes Intel's P4 3.06ghz.
If you run it on a 1ghz processor, you'll strangle it's power. The 1ghz processor will simply hold it back and you'll have wasted a lot of money. If you're thinking of spending that kind of money, I'd be inclined to think about a whole new P.C. If you find the right deal, it can sometimes work out as cheap as upgrading.
But don't install one (fantistically good) component in your existing PC and expect the rest of your hardware to keep up with it. It won't. It will simply bottleneck everywhere, meaning you'd actually experience the same speed as if you were running something like a GF2 MX200.