Hi I am also having trouble installing Windows onto my perc 5i. When I use the Windows 7 RTM it finds my raid 5 partition fine, but will not install onto the partition.
Everything went through fine on the PERC bios.
My original boot on another hard drive finds the Raid 5 easily enough and can do tests on the hard drive. I just can't install windows onto the hard drive.
I get an error which says "Setup was unable to create a new system partition or locate an existing system partition. See the Setup log files for more information."