Windows Vista Home Premium Won't Start and error "Notification dll has not been registered, program will not work correctly.”

I have an XPS laptop that is only a few months old and now I get a black screen after choosing to either start windows normally or safe mode, and I eventually get the error ""Notification dll has not been registered, program will not work correctly.” 

I have tried to start it in safe mode, I have tried to start it from disc, I have tried to disable wireless in case that's the issue, I have tried to repair (it says it doesn't find errors.), and I have tried to connect it to a monitor to see if it's an LCD issue (but it doesn't recognize my system).    Media Direct allows me to see my photos, but I can't access my desktop or regular windows interface.

I do not want to reinstall Windows since I will lose some things that were not backed up.

Does anyone know:

1.  How can I fix this?

2. How can I make sure that it doesn't happen again?