Installed Latest Update - System is now frozen with "Operations are in process. Please wait. Screen!

I got a notice of an update being available so initiated the update process. Part way through the installation, my system started acting up. I put up with it for about an hour but finally decided to restart the system. I then got a blue screen with the message, "Operations are in process. Please wait." I left it alone for about eight or nine hours and then checked in on it and it had not changed! I now can not get my system to re-boot! Help - what do I do? I'm dead in the water and had to use my work laptop to get this message in!

Thanks in advance for your input!

Fred M3