Since the HDD controller on your motherboard supports Raid, it probably needs a driver loaded during the start of your Windows installation. Some motherboards have it on a floppydisk or on a cd provided with it. If it's on a cd you will first need to copy it or use the floppydisk creation program if provided on the cd to have the necesary files on a floppydisk. Unfortunately Windows XP will only read it from that media.
If you have done that you will see that directly when the blue setup screen comes, you have an opportunity to press F6 to load additional drivers and you need to do this. Once it has loaded these drivers, you should be able to see your harddisk and select it to install Windows on.