Help with .htaccess override

I have the trial version. Mod rewrite is on, .htaccess is in websites root but I get 404 error. All I can think of is .htaccess override. I tryed to modify httpd.conf and wrecked apache. I cant afford the server being down so I need detaild instructions or someone to the job for me.

If I get it t0 run I purchase 2 licenses

Now I`m confused I made the google test on one of my other domains and it works. Could it be due I run the site from this location ns1.bosrap.com/~common/ and not from a real domain ?