Problem with FTP access and error logging

Hi

I have recently installed WordPress 3.0.1 to a Windows host. The site is live and I can add posts and comments etc.

My main problem is that I’m not able to make any changes from the WP dashboard requiring FTP access – e.g. updating the Akismet plug-in or installing a new theme (I’m using the correct FTP login details): I get a 500 – internal server error.

Does anyone know what the problem might be?

The tech support at my hosting company advised me to create an error logging file and include this code at the start of wp-admin/update php (the file returning the error message):

ini_set('display_errors', 1);
ini_set('log_errors', 1);
ini_set('error_log', dirname(__FILE__) . '/error_log.txt');
error_reporting(E_ALL);

That hasn’t worked – nothing has been written to error_log.txt.

Can anyone advise as to how I should enable PHP error logging – e.g., a suitable file that would be referenced in all tasks, including the wp-admin side of things. If I can determine what the error is, then hopefully my hosting company can help fix it.

Thanks in advance for any help (I should point out that I’m very much an amateur when it comes to coding, so please use small words!)