Just installed the software onto my site via a subdomain.
When trying to access the admin.php file in /zp-core/ firefox 9 reports can't find file.
Although it is there.
Installed through host's quickinstall feature in cpanel.
The mysql database is there. I did make sure htacess was writeable.
What do I do now?

Ok apparently the software does not like being in a subdomain.
works just fine normally.

Zenphoto likes to be used on a subdomain. But you can use Zenphoto only under ONE domain. So www.yourdomain/zenphoto and subdomain.yourdomain.com will not work together. You need to decided what to use (limitation of using mod rewrite and htaccess which requires a rewrite base).

Installed through host's quickinstall feature in cpanel.

If you have problems with that please contact the provider of that. As clearly stated on our install page and the forum rules we neither recommend nor support these tools.