How can I find out which drive in my RAID has failed?

Episode 1051 (1:28:13)

Ed from Los Angeles, CA
RAID

Ed has a custom built Windows 7 computer with 4 1TB hard drives in RAID 1+0 configuration. He rebooted it and now the operating system is missing. RAID 1+0 is striped and mirrored, meaning that if one dies, then he can swap it out, recover the data, and continue. He's using the RAID that's in the Asus motherboard BIOS. Can he recover the data without rebuilding the RAID? The key is to find out what drive has failed. There is a RAID tool which can help, but he can't get the computer to boot.

Ed should run the RAID utility in the Asus BIOS, which should tell him which drive failed. This might be a job for a local expert.