erro em .htaccess

boa tarde alguem pode me ajudar to usando

RewriteEngine On
RewriteRule .* index.php

na raiz do meu site qdo executar ele da erro

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, weliton_sis@yahoo.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

alguem pode me ajudar???