|"Creative Labs Soundblaster CX4870"|
Google doesn't reveal a CX4870, it does show CT4870 which is very old.
Post #4 here may help.
More drivers here, select the right one for your version of XP, 32 or 64bit.
I use this tool, if the above info fails.
If all the other drivers are working well, leave them alone, only update the sound card.
Update your system drivers on the fly.
SlimDrivers is a software application that was designed in order to locate and get the latest drivers for your installed hardware.