Depends. If you are looking to do hardware RAID, you set this up under your MB's bios before installing Windows. The resulting drive will be available for use in Windows but you will not be able to make any changes to the partitions using Windows 7. Alternatively, you can leave them untouched and set up software controlled RAID via Windows7

Some people trust HW controlled raid more, others like the convenience of the SF solution.

The answer as to how you do this the HW way, as you specified, depends on your MB & it's BIOS. You may have RTFM for that I'm afraid.

With great power comes Awesome irresponsibility.