You need to go through the Windows installer and watch the bottom at the start for an option "push F6 to install 3rd party RAID drivers" or something similar...then you need a floppy disk with your motherboard SATA drivers to install and you're good to go
if he's already got windows running on an IDE then all he needs to do is plug in the SATA drives and assuming he's installed all drivers for his motherboard it should recognize it right away.
gaaras explination is only for installing windows on a fresh SATA drive
DID you enable the drives in your BIOS I saw a really confusing DELL bios the other day IT HAD PATA and SATA mixed and it took a few passes to figure out how to enable the SATA drive.