OK. Thanks for the reply, but way too late.
I ended up restoring to a point last week and they lost a week's worth of data.
Anyway, the Rebuild choice was not in the menu and it never offered to rebuild it when it was "Degraded", so I never got to make that choice.
The hot-key is "CTRL+I", just in case anybody else reads this.
The NSH file I was looking for was to UPGRADE the version from 7 to 8 or 9, which I saw had a Rebuild function in the main menu. Never found a way to update this.
I have found since that they have "moved" the IMSM (Intel Matrix storage Manager) to the newer IRST (Intel Rapid Storage Technology). Which, I'm sorry to say, RUNS IN WINDOWS, instead of from the boot environment, so it's useless if you can't boot to the array. Stupid.
Anyway, what I DID do was to get another disk, set it up as a normal SATA (no RAID), set the BIOS to boot to it, install Windows SBS 2008 to a point, install IMSM and/or IRST within Windows, then run an array Rebuild.
NOTE TO ALL: The rebuild "re-ran" 3 times (4 times total, from 0% to 100%) and took three solid days to rebuild a 1.5TB array (3x500GB disks). And when it was done - it was STILL DEGRADED!
I deeply suggest to all to do a full backup the instant you see a "Degraded" array.
One more thing: I added a fourth 500GB disk and created a 2TB RAID5 array, then did a Windows SBS Image restore, it re-created the 1.5TB volume. I then had to "expand" the volume using the "Manage", Disk Sorage, Expand Volume function.