You'll have to disable RAID in you BIOS.
Also, if the drive is brand-new, it has no partitions.
Via disk managment you can create a partition.
That partition needs formating. Via disk managment or explorer.
But the problem is the disk change.
You'll need to install windows all over again. The core system files are unaccessible normal way and only accessible via repair mode console. It is too much of the work (manual copy file by file) and installing xp again is easier and simpler, but one problem there is possible: You said that you're not familiar with sata. Neither is XP. You will need (old XP version) a floppy disk (and a floppy drive) with so-called F6 drivers for the sata controller. That you can get and make with mobo bootable CD. I had quet a hassle with my asus a8n sli mobo and xp installation.
Maybe you can bypass the f6 drivers if you format the HD now and then switch them.