Joomla!®Plug

hi

first, sorry;
I dont speak english very good;
I hope you can understand me.

I upload files to my site.
-I run http://mysite/joomla/Joomla.Start.php
-start install
screen said:
===========================0
Install Joomla software on the fly!!!
Package succesfully downloaded to /home/httpd/vhosts/ccaf.net/httpdocs/joomla/Joomla_1.0.8-Stable-Full_Package.zip

Launch Joomla installer!
Files succesfully copied to /home/httpd/vhosts/ccaf.net/httpdocs/joomla
==================================0


-I clic in 'launch joomla installer';
that clic goes to "http://mysite/joomla/installation/" but
that screen said:
=================================
Forbidden
You don't have permission to access /joomla/installation/ on this server.
=================================

I have aplicated permison 777 to joomla folder but the ftp software said me:

Apache/2.0.46 (Red Hat) Server at www.ccaf.net Port 80

550 CHANGELOG.php: Operation not permitted


What can I do?