Hi Dan:

A friend of mine had similar experience a few months ago, and he had to reload the OS (I helped him since he did not know how to do it) Needless to say, you have to download the proper OS version and have those 12-13 floppies.

I hope you have beackups of your registrations, user styles, etc.
That seem to work. I hope I am wrong and is something easy.
Best luck and Merry Christmas.