Short story:
You're much better off upgrading everything. Your possibility of success is vastly higher.
More detailed story:
That sound card is OLD. I found an XP driver here: (
http://ar-domena.com.pl/-live-drive-ii-/). So yes, it will work on XP. Problem is: will the rest of your new hardware? Newer hardware that you're interested in buying may or may not have XP drivers - most still do but some of the latest and greatest do not since it is much easier to go with the flow and abandon backward compatibility like MS did with the Win7 platform. Well, technically they did that with Vista but Vista doesn't count since it sucked so hard.
If the rest of your hardware is as old as this sound card you are absolutely going to need to replace your power supply when you upgrade. Unless you get a motherboard with video built in you're most likely going to have to replace your old video card as well.
Even if you don't - you're going to have problems. I guarantee it. The older hardware was *never* tested with the newer hardware. The odds of driver incompatibilities (bugs) and annoying blue screens because of them is exceptionally high.
Do yourself a favor and just upgrade everything. PCs are obscenely inexpensive now as long as you stay away from the latest and greatest. You can build yourself a smokin' recording system for under $1000. And that includes the price of the recording interface itself as long as you want to stay simple (like your Creative solution currently is).
Also, while I'm busy ranting away here, if you are unfortunate enough to be running Windows Vista right now I strongly encourage you to upgrade to Win7. The difference is night and day. You will be very happy with that upgrade.