I've got a fairly old MB, ASUS P5B-E with ICH8R chipset, and Intel option ROM version 6.0.0.1017.
For a long time I had 4x500Gb drives configured as Matrix RAID (RAID0 and RAID5), working without any problems under Windows 7, booting from RAID0.
And today I did two things simultaneously:
1. Added a SanDisk Extreme 2 240Gb SSD
2. Installed Windows 8.1 on it
And in the process of installing, Intel ROM on boot started to show RAID disks as "incompatible", and "No RAID arrays defined".
Removing SSD does not solve anything.
Another HDD on the same controller is shows as Non-RAID disk, as it should, only those which were in RAID are "Incompatible" - incompatible with what I wonder?
What is surprising, however, is that from Windows 8 itself both partitions are seen and working properly - it's only BIOS which can't see them, and I cannot therefore boot into old Windows 7 installations.
There are no separate BIOS updates on Intel site, and no BIOS updates on ASUS site for a long time.
Is there any known way to solve this? What could cause BIOS to stop recognizing the drives?