Hello Kevin and welcome to the forum.
have not ever seen anything like this!
Me either.
I suppose the best first step would be to check the system BIOS and confirm that the Hard Disk is still being recognized.
If that is confirmed and you are certain beyond doubt that it was the updates then perhaps booting to the installation media and performing a System Restore to a restore point prior to the updates having been applied might be a reasonable second effort.
Third (for me) would likely be pulling the drive and connecting it to a second system and seeing what's what, and performing a bit of backing up of critical data.
Failing that I suppose booting to a Linux Live CD
http://www.linuxmint.com/edition.php?id=159 may allow you...