i have solved the problems, infact i download again original file htaccess.txt and then i renamed to .htaccess.

Ok for link Joomla SEO powered by JoomSEF that i cancelled.

I have renamed htaccess.txt to .htaccess but i see always this: "...a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request."
I have removed Options +FollowSymLinks but the problem remains.
thanks

I have renamed file htaccess.txt to .htaccess and suddenly appears error 505 in every page. So i created .htaccess.bak to restart website. that's all.

and at the end of the page i have always: Joomla SEO powered by JoomSEF. www.archihouse.net

mod_rewrite is ok. I talked with server manager and he said me that evrything is configurated correctly. I hve always the problems of: 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request. The url is correct but i don't see the page.
Thanks.
Alex

I have installed artiosef but it's not playng because when Global SEF URLs is enable i see in every page error 404 and i see only the homepage. Can you help me please?
Thanks
Alex