Windows 2000 pro all da way. I used XP Home briefly. I had to walk away from the computer, its like windows without administrative privilages. I've heard some good things about XP Pro but not thinking about upgrading just yet.
Asus A7N8X Deluxe - Rev 2.0 - Bios Ver. 1007
AMD Athlon XP-M 2200+ - @ 11x188 = 2Ghz (1.75Vcore)
ATi Radeon 9700 Pro (Almost as good as my old 5950U!)
Corsair 512MB XMS TwinX Low Latency DDR 400 - @ 188Mhz
3dmark03 Score: 5086