You may have two separate problems. Audio is either built into the
motherboard, or on a separate PCI card. RAID is a piece of hardware,
usually on the motherboard, but also possibly on a PCI card, that controls
stroage devices, like hard drives.
Many motherboards come with RAID controllers, but most PCs do not use them,
since they have only one hard drive, and that is usally attached to a
standard IDE controller. Note that a PC may have multiple IDE controllers
and multiple RAID controllers, with the possibility of handling 6 or more
hard drives or other storage devices (e.g., CD, DVD, ZIP). Thus, it may be
perfectly normal on your PC to have a RAID controller that is not working,
beasue it was not needed.
As for sound, check the obvious first: wires, mechanical on/off switches,
software on/off switchs (like mute, or volume control).
Next, check for a yellow "!" or "?" on something that sounds like an audio
device under "sound, video, and game controllers" in the XP device manager.
A RAID controller should not appear listed under this category.
Finally, you could try obtaining and reading the manual for your PC or
motherboard. These are rarely available on paper, but are often included on
a CD that came with the hardware, or as a free download from the
manufacture's website.