On WordPress’ page about using permalinks, it gives steps to enable “pretty” permalinks. I have non-shell hosting account at 1and1.com, and I had use only .htacceess to make it work. Even though the WordPress’ instruction says you have to set FileInfo directives allowed, but I found that it actually causes Internal Server 500 error.

I had the following piece of code in .htaccess, and now it’s working fine.

# BEGIN WordPress

Options FollowSymLinks
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

# END WordPress