Power up the server, boot to the Ctrl R bios. Delete the array, then configure a disimilar array, such as a RAID 0. Initialize it. this will remove all traces of the first array and MBR; Then delete it, and recreate your RAID 1 and initialize it. Restart the server on the Windows 2012 DVD and install in the UEFI mode. It should contain the driver for the PERC 700.
Regards,