A million thanks to esmi.
I uncommented the mod_rewrite line in my httpd.config file, restarted all services in Wamp, and tested things out. Guess what? It works. I can now view my posts and comments either from my dashboard or from the site without any 404 errors.
I don’t really understand why it works, but as long as there are smart coders like esmi, I can get by with my non-programming skills.
Thanks again!