Attempted to install Win 7 on old dfi lanparty MBO. Have 2 drives, software striped. They are hd0 and hd1. Have SATA drive for OS which is hd2. When installing Win 7, it clearly showed hd2 but when I tried to continue the install, "Setup was unable to create a new system partition or locate an existing system partition" appeared. No amount of deleting, creating, etc. would change the message.
After some thought, I disconnected the stripe drives and viola! Win 7 installation proceeded. Apparently even though Win 7 reported the right drive (hd2) for installation, it really attempted an install on hd0 which, being a stripe drive, caused a failure.
At the point of failure, there was a message to look at the log files but without any apparent way to do that at such an early stage in the boot process!