I have been trying for 2 days to get W7 pro to install on RAID5 set up through the motherboard. I have 4 identical 2T hard drives which are no problem to set up as a 6T RAID5 array on the motherboard. The install starts with no problem, I load the RAID drivers and convert the array to GPT format and point the install to the 6T GPT drive which the install sets up with the 3 partitions required but then the install stops and says it can't install because the computer will not boot to the created partition.
Bearded Dan I am now experiencing the exact same problem, and with an MSI board. I wonder if possibly the RAID BIOS isn't the culprit. Did you ever find a solution?
What I came up with is that WIN 7 will only control a 2 TB section for it's drive. I set up the RAID array with a 2TB area for the operating system and the balance as a second array and it's been working fine ever since.