Been told that my hard drive is weakest link on my pc performance wise and believe its currently IDE???

Ive bought 2x western digital sata drives, what do i need to do?

Im 99% sure the motherboard will take sata. I would like it to boot with windows XP pro from the sata and so wanna transfer windows i think????

PC Spec:
Gigabyte Ga-8ipe1000PRO-G S478 865PE ATX Sound GIG LAN Firewire USB 2.0 Retail Box

Intel Pentium 4 2.8GHZ 800FSB SKT478 512Kb Cache Retail Boxed

Seagate ST3120026A 120GB 7200rpm 8mb Cache Barracuda 7200.7 Plus - OEM

4x Samsung Original 512mb PC3200 DDR400 184pin Memory Module

Sapphire Radeon 9600 AGP X8 256MB DDR DVI TV-Out Retail Box