Detecting SATA drive

Ok… my bios will not detect that i have a sata drive on the computer. but when i boot to the windows xp cd rom, I am able to install no problem. But of course after the install it doesnt see the drive again and tells me there is no boot media. what the heck is going on?? usually widnows wont recognize it not the computer. Can someone please point me in the right direction here? im getting annoyed.