Windows XP Installation Error

XP would not install after I told it what drive to use, because it wasn't a "windows xp-compatible partition". However, it never gave me the option to format it, so I don't know what I was supposed to do about that. After reading this: http://www.techsupportforum.com/microsoft-support/windows-xp-support/321356-disk-does-not-contain-windows-xp-compatible-partition.html I deactivated a DIFFERENT SATA hard drive and it installed fine.