2nd Hard drive disappeared after Windows Update

UPDATE: Success!

None of the above options worked.
The drive was only visible in disk management, and not recoverable by any data recovery tools.

Partition Wizard only reported "Bad Disk" on scanning, and Power Data Recovery couldn't scan or detect any data on the disk at all.

I tried unplugging/replugging with no luck.
Tried moving to an external enclosure with no luck.
Moved back to the PC and tried several free tools for repairing/recovering partions and partition tables with no luck.

At this point I realized that all of the files for the new business I started last month were on this drive. A few files were on jump drives, but EVERYTHING was on this drive.
I was ready to shoot myself.

As a last resort I was ready to try to initialize or reformat the drive in the hopes that if it was recognizable in some form I might be able to finally recover some data.
I went into Disk Mgmt again to initialize, but now the disk had changed status to "Errors" and initialize wasn't an option anymore.
Now I was really ready to shoot myself.
Instead, I did some reading on the errors staus which lead me to other solutions for "Offline" and "Missing" statuses.

On a fluke I decided to change the drive to "Offline" and back to "Online".
Hallelujah!, One of the partitions was recognized and back with drive letter and volume name, and the other was reporting as healthy but with no drive letter.
(I was mistaken earlier. I thought it had 3 partitions, but it only has 2)
I assigned a letter and path to the unknown healthy partition and bingo, it was back with the original volume name and accessible again.

I've already backed-up the latest files that were only on this drive, and am now backing-up all the rest of the files again just in case this drive is on the way out.

Normally I have an automatic backup drive plugged into one of the USB ports on this box, but a couple of months ago I needed to use both ports for another drive and a tablet, and never plugged it back in.
I can only hope that I've learned my lesson...
Sheesh, what a night.

Thanks to all who helped with suggestions and advice.

Cheers!

Reps spread around for all the help and solid advice.