Need advice on motherboard and CPU

[nanllyn]

I built a computer for my husband about 2 years ago or so. It is a MSI KT3V
specs:http://www.msi.com.tw/program/produc...il.php?UID=385
with a Anthlon XP 2800+ and 1 gig of DDR 333 Ram, MSI Nvidia FX5800 card.
I believe the motherboard is going out as we can not get any floppy drives to work, the cd rom locks up sometimes and the whole computer freezes very often, where you have to force it to shut down but holding the power button for 10 secs. And it takes almost 4-5 minutes to fully boot up.
This computer is plenty fast enough for what my husband does. He surfs the net, emails and plays older games such as Viet Cong, Command & Conquer and such.
So my question is, is it worth just changing out the motherboard or should I build something better? I don't have much money to spend at the moment but here is what I was thinking if I built one.

Athlon 64 3200+ Venice 939 CPU (ADA3200BWBOX) (or could I go with a 754 socket?)
Gigabyte GA-K8N Pro-SLI 939 or GA-K8N-SLI (I have Gigabyte and like it but would Asus, Abit or MSI be better boards?)
Corsair XMS 1GB DDR400 Dual Channel Ram
THermaltake TR2 W0070 ATX 430W Power supply
The hard drives, dvd-rom, case,etc I will reuse. The problem being this new build is really way more than I want to spend and possibly more power than my husband needs. What do you think? Also if you have opinions on any of my choices please let me know.
Thanks,
Nancy

[Foosa]

Corsair value select for your ram would put you a few bucks cheaper and is good stuff(over 1000 reviews at newegg.com they must be doing something right).
http://www.newegg.com/Product/Produc...82E16820145440

But for motherboards look in to asus.
http://www.newegg.com/Product/Produc...82E16813131569 this looks to be good for you. As i doubt you will be using the sli feature at all.(2 video cards) So unless you are going to use sli, that can save you some more green.

other than that i like your cpu i would go with a 939 just because if you need/want to later you can buy a more powerfull cpu instead of a cpu and mobo if you went 754(which has one foot out the door as is).

[glc]

You will not be able to reuse the video card - the 939 boards are PCI-Express, not AGP. The Thermaltake power supply is not suitable for a PCI-Express build either, you need ATX 2.0.

Have you run full diagnostics on the computer yet?

Ram - www.memtest.org

Hard drive - download from the hard drive manufacturer

It may be a bad motherboard, but it could be ram, hard drive, heat, or power supply. Have you cleaned out all the dust, especially in the heatsink and fan? What about the video card heatsink and fan?