Re: What to do now i have 3gigs of pc2 4200..
You shouldn't have to change any settings if your motherboard supports that speed of RAM.
3GB's is fine, and its also the max Windows XP 32bit will see.
Running idle, I have around 1.5GB's free of RAM, and I have 2GB's.
Least you know you won't have to upgrade for a while
Abit IP35 Pro / Q6600 G0 / Zalman 9700 / 8800GTS 640mb / 4x 2GB Corsair XMS / X-FI Xtreme M / 1x 1TB / Antec 900 / Logitech Z-5500 / Samsung 20inch