If you are using the "Build Utility", then you can't use the driver.
Dump the "Build Utility", as that will be no use to you here.
Download the 2008R2 driver I linked in a previous post, run it to extract the files, put the extracted files on a USB flash drive (or a CD). Insert USB flash drive. Boot to the Windows disc. When it says it can't find any drives to install to, click the Load Drivers link in the bottom-right corner, then browse to the location of the driver.
Keep in mind this is for the onboard S1x00 RAID controller. If you aren't using that controller, then this will NOT work. Which controller are you using?