I finally decided to change the setting of my wordpress multisite from sub-directories to sub-domains, taking into consideration the potential complications I proceeded as follows;
I followed the steps given in the article Migrating Multiple Blogs into WordPress 3.0 Multisite and I also used a completely New Database for the new installation.
I performed steps 0 to 4 successfully and on step 5 the test site (marketing) was created but I can't access its dashboard. I get this message on my browser:
The requested URL /wp-admin/ was not found on this server.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
Apache Server at marketing.quickinsider.com Port 80
I am with Godaddy Hosting Services having a Shared - Deluxe - Linux - Hosting Plan and this plan includes Apache mod_rewrite and wild card sub-domain can be setup. I believe to have done everything correctly with my hosting account and the problem seem to be with wordpress creating the sub-domain sites correctly.
Please I need any form of help!!!
Thanks in advance.