Currently, I have a Gigabyte GA-K8NS-939 motherboard with AGP 8X and am looking to upgrade to a PCIE motherboard and video card. And be some what future proof. \
Dear DCU,
socket 939 is not future proof at all: socket 939 motherboards and CPUs are being discontinued now. They are still sold in stores, but, there is not going to be much in the way of upgrades in the future.
Since you have to get a new motherboard anyway, it would probably be best to switch to either the AMD socket AM2 version, or, to Intel socket 775. Both of these are going to have quad core CPUs available at decent prices in a few months or so.
You will have to swap out your DDR memory for DDR2, but, DDR2 has gotten so incredibly cheap in the past month that it is a good time to do it--costs about half as much as DDR 400 right now.
If you can buy a CPU that costs about $200 and up, go Core 2 Duo. For less than $200, get an AMD socket AM2 CPU.
Get 2 x 1GB of ram--about $75 dollars or so now!
Since the newer CPUs run cool, you should be able to re-use your case and power supply.
Also: you can use your old system as a backup/server machine....hey, are you backing up on a regular basis? Probably not....keep the old socket 939 tucked away somewhere, fire it up to use as a backup.....
HTH,
NXIL