Library damaged error message

I have the problem - but have no idea about the tecnicalities you have been forwarding as solutions.  I am a user and not familiar with drives - etc.

Is there a step by step solution.

At the moment endnote is frozen, I can’t close it or open it.  The error message will not shut, so can’t get access to the program.

I have a lot stored on end note, and do not know where to start