Hostgator WordPress problems with htaccess

I’m using WP 2.8.4 installed via Hostgators fantastico.

Couple of questions; where is the htaccess file?

I see one in mail folder, in etc folder but in public_html and www folders there is no htaccess file.

And when I make one in notepad, like this;

RewriteEngine on
RewriteCond %{HTTP_HOST} !^www.yourdomain.com$
RewriteRule ^(.*)$ http://www.yourdomain.com/$1 [R=301]

It gives me this message back;
http://i31.tinypic.com/vpvo0y.jpg

Mind you, yes I did change the yourdomain part.

So how to make http://www._________ always appear in the address bar? I hate it when it gets removed.

Also, is it ok if I turned the indexing off on every folder except of public html and www ?

Thanks