I don't recommend doing what you did - setting all three HDDS online is optimistic, but resetting the Controller and importing the configuration from the HDDs should only be used when the Controller is replaced, or you've tried everything else and it's your last option before rebuilding and restoring from backup. Instead, I would take a look at the RAID log and see if you can determine which HDD failed first. If you can, leave that one Defunct and set the other two online and the Operating System should boot. Then, place a service call to have the HDD replaced - only the one that failed first. If you can't, then by process of elimination, you can set two HDDs online and leave one defunct to try and boot the OS. It's tedious, be effective. When you get the OS to boot, run CheckDisk - DO NOT REPAIR ERRORS FOUND!!!!! Since more than one combination of Online/Defunct HDDs may boot, you're looking for the one with the fewest errors detected. That combination is the one where you correctly identified the HDD that failed first. When you get there, place a service call to have that HDD replaced.