Please excuse my mistake - I actually meant 'gen_htaccess.php' and not 'gen_dump.php'
So when you execute gen_htaccess.php, it will show you some contents in your browser. Please copy the entire contents (Ctrl-A) and paste them in a file named '.htaccess'.
You can now place this .htaccess in your site's root folder.
P.S. On Windows, the OS will not allow you to create a file with no extension. If this be the case, just copy any .htaccess from with 'couch' folder and then edit it to paste the contents mentioned above.
On last thing, once prettyURLs are activated, you might find that all your images and CSS paths no longer work. That would happen if you are using relative paths with them.
This can be rectified by placing a '/' before the paths.
Hope this helps.