Windows screwups

In the year before windows 95 was corrupted over this last xmas, I had seen many error messages generated by windows. This morning was a new one for me. It turns out my system registry had an error in it and I had to reboot. It's mild as error messages go, but what in the world would cause such an error when the computer has been running for over a day?

Windows problems again

Okay, that error message just popped up again on me. Here's what it says:

Registry Problem
Windows encountered an error in the system registry. Please close your programs and restart Windows now.
You may lose some of the information from the current session. Restarting will allow the registry to reinitialize.

What the hell is that? I don't need new problems with my computer right now during my internship.