hardware raid has to be set up using special hardware to do it, in that case it's done at a bios level and you can protect your drives using RAID and thus protect your windows installation as well.
you can create raid arrays in windows without hardware, across many types of disks if you want.
you litereally click on a blank disk and select to make it a part of a raid set, in order to do this you have to have other blank disks.
you can (i've seen it done before).
create a system partition that is not raid protected, (as you can't hardware raid only software raid in this case).
then use the rest of that disk and another disk to form a raid set to protect your data.
usually in this case you're better off having a system disk for the windows install and two other disks for the raid array you want to create.
edit - http://www.tomshardware.com/2004/11/...pen/page3.html
that should help