RAID is not software by itself, RAID is a specification on how to use multiple disks to combine into one large virtual array. What you are going to use is an implementation of RAID, rather than RAID itself.
It may be obvious, but any RAID engine differs, you can have Software RAID, Onboard RAID or Hardware RAID. If you're using the motherboard onboard RAID, you're using Onboard RAID. Note that this is not hardware RAID since all work will be done by windows-only drivers; its a software engine. That's ok though.
Generally these are the steps you must take:
- install HDDs and connect to motherboard onboard SATA controller. Some motherboards have multiple controllers; pick the chipset-supplied ports not any additional "RAID CHIP" or something. Often if a motherboard has more than one controller, some SATA ports have different colours.
- Go to the system BIOS and set the option "SATA transfer mode" to "RAID" (other settings: IDE/Auto/AHCI). Some BIOS work differently and can enable RAID-mode per SATA port. Look your manual.
- Boot up until you see the onboard RAID printing something on the screen, often giving you an option to enter RAID Setup. "Press F3 to enter RAID setup" or something. Do this and here you should see your two drives and able to set them in RAID0. This procedure is in your motherboard manual.
- Insert windows cd/dvd and let it boot. After getting a coloured screen, it prompts you very shortly to press F6 to install additional drivers. Do this quickly, and you'll get a screen where you can load drivers from USB-stick. You need to have an USB-stick with decompressed RAID-drivers for your motherboard or chipset. These can be downloaded from theit website. Note that you don't have to use floppies like you have to with Windows XP.
- After it found your drivers, it will see your new RAID array. You can make partitions etc, everything will be like its just one big drive. Install as normal.