Fatal error: require_once() - After moving htdocs to another drive - opencart

Question

Fatal error: require_once(): Failed opening required 'C:\xampp\htdocs/system/startup.php' (include_path='.;N:\New folder\php\PEAR') in N:\New folder\htdocs\index.php on line 23...
This error is showing on localhost server when I had to uninstall XAMPP folder from c: drive but I took backup of htdocs and MySQL folder and when I reinstall XAMPP in n: drive and copy paste old htdocs and MySQL to new files, this error is showing...
2nd problem which I am facing is that my SQL is not running on XAMPP control panel whereas
Apache is running without any issue...
What can be the reason for this error?

Answer 1

OpenCart uses two config.php files, one at root and another in admin folder. In these files some global variables are defined containing also paths to installation folder. When you installed the OC, it automatically find the paths and write them into both config files.
But when you changed the directory of your OC (moving on disk, uploading to server), they don't update automatically and you need to do this manually:
// DIR
define('DIR_APPLICATION', '/path/to/public_html/catalog/');
define('DIR_SYSTEM', '/path/to/public_html/system/');
define('DIR_DATABASE', '/path/to/public_html/system/database/');
define('DIR_LANGUAGE', '/path/to/public_html/catalog/language/');
define('DIR_TEMPLATE', '/path/to/public_html/catalog/view/theme/');
define('DIR_CONFIG', '/path/to/public_html/system/config/');
define('DIR_IMAGE', '/path/to/public_html/image/');
define('DIR_CACHE', '/path/to/public_htmll/system/cache/');
define('DIR_DOWNLOAD', '/path/to/public_html/download/');
define('DIR_LOGS', '/path/to/public_html/system/logs/');
E.g. if you have old paths like this one:
define('DIR_APPLICATION', 'c:/htdocs/catalog/');
And now you moved it to n:/New folder, change all the paths accordingly, e.g.
define('DIR_APPLICATION', 'n:/New folder/htdocs/catalog/');