GET RID OF VISTA!!!!! Don't use it at all. Go get XP PRO 64 BIT.

Vista is a memory hog.

Ditch the sound card unless you are into sound and have the speakers/setup to back it up.

If you can get a quad core and put the O/S on one cpu and each wow client on the others, use the last for music or nothing and keep it for scaleability in the future.

Upgrade to 8 gigs and use 2 gig sticks each with heat sinks built in.

Get rid of that WD hard drive. WD is the WORST hard drive makers out there. Why do you think every cheaply made computer has one?

Go with Maxtor, their warranty and support are solid along with making a good product is a win win!