Computer format

Hi. I've been using calibre for over a year now and I have an extensive collection of books. I also spent a lot of time playing around so it looks just the way I need it to look.

But I now I need to format my computer and I really don't want to spend hours changing everything to the way I like. The library, I know how to backup and bring back.

What I want to know is what exactly do I need to back up to keep all my custom preferences, from the main program and from the plug-ins. Is it enough to copy the program folder? Or do I need to be more selective of what I copy into the new installation?

Thanks in advance for you help.