Dokuwiki has been installed into ${INSTDIR}

With Apache, this directory must be granted at least with this:
     AllowOverride Limit

You should point this to the DocumentRoot of your web-server:
   # ln -s ../dokuwiki /var/www/htdocs/dokuwiki

Then add to your httpd.conf:
   <Directory /var/www/dokuwiki>
	AllowOverride Limit
   </Directory>

Proceed to complete the installation by opening install.php in your browser.
If you are upgrading your installation, don't forget to remove install.php.