Localhost install preview not showing

I have a localhost install and firefox browser. I downloaded a backup of my website and loaded it locally in order to edit and play with extra plugins. Everything worked fine. I closed down and restarted my computer and when I started everything up I could access the dashboard and edit pages but the preview only gives a 404 error. The actual site loads correctly on its home page but the menu doesn’t find pages either.

I am low level wordpress user, what to do? How do I readdress correctly?