After putting .htaccess to site root directory all drupal links goes "The requested URL /XXXX was not found on this server"

Hi.
My trouble starts when i tried to override php.ini setting "upload_max_filesize" through .htaccess file. The whole content of .htaccess was:

php_value upload_max_filesize=20M
php_value post_max_size=20M

Since that i`got only front page of my site working. All other site paths showed as:

404 Not Found 
The requested URL /XXXX was not found on this server.

I can`t do anything with my site. This behaviour stay even after i delete .htaccess from site root.

How i can fix this and return site to normal state?