Installation error but meet all requirements

Got this message after installing everything –

Fatal error: Class ‘Zend_Db_Adapter_Abstract’ not found in /home/XXXXX/public_html/piwik/libs/Zend/Db/Adapter/Pdo/Abstract.php on line 45

Verified with my webhost that I meet all minimum requirements.

Each of the accounts on my server has its own cPanel. I have been trying to install on one of those accounts – must I instead install on the root server?

Also, is there an administrative interface available for all sites that I have Piwik installed on, similar to that found in Google Analytics?

Some files are not uploaded correctly

I re-FTP’d and that did the trick. Thank you!