Raid 1 failure causes

Hello,
I also have a New computer, only a few months old, that I built using a RAID 1 configuation using a SIIG,Inc. SATA II PCIe RAID card and two 500 G WD hard drives, With Windows 7 64bit. It worked good for several months. Then after down loading Windows up-dates and rebooting, it came up saying no bootable device, I attempted same several times, same message. I replaced the RAID control card with no changes. In the RAID Bios it gives me the messages; degraded RAID 1 set and Invalid RAID Drive. Is one of the Drives bad and how do I test it, also how best can I restore the RAID to operating condition? Thanks
Ken

If you downloaded a controller driver update and it installed it may well have knocked the RAID driver out and replaced it. Windows will being looking for the original driver and the controller may not be able to communicate with the drives under their previous configuration.

Disconnect one of the drives and put it on an non raid SATA controller. With luck you will find all your data there. If not try the other drive. Then assuming you can get your data then copy it to another drive. Reset the RAID 1 from scratch. It will likely come up as a valid RAID. Then you will have to reinstall Windows.