Can’t view a page and “About” page redirects to home

Hi everyone,
I’ve just installed WP in a subdirectory:
localhost/wordpress/news

And in WP, the settings are:
WordPress address (URL): http://localhost/wordpress/news
Blog address (URL):http://localhost/wordpress

When I create a page (“volunteer”), the url it generates is:
http://localhost/wordpress/volunteer/

But I can’t see the page because I get this error:

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

As for the About page that came with wordpress, it seemed to redirect to the root directory:
localhost/wordpress/

I’m not sure at all what’s happening here. Is it something in the .htaccess that needs to be edited?

Thanks for any help!

Rick