I dont know why i cant install my Windows XP to my PC. But my Windows Vista CDs works. I wonder why. Tried to reformat it many time. But just when i finish formatting, an error says "Unable to open XP setup" or something like that. Right now, im using Vista. Really dam heavy using it. Anyway to solve it?

My PC.
Intel Dual-Core 2.80Ghz, 1GB RAM DDR, Nvidia GeForce4 MX4000 64MB, 80GB ATA hardisk