Q:

Language switching fails for multilingual drupal site

I'm trying to build a multilingual web-site with Drupal 6 and currently I ran into a problem switching UI language. Switching language from the default one using language switcher block doesn't work and displays error message:
The selected file could not be copied, because no file by that name exists. Please check that you supplied the correct filename.
The following message gets written to a log:
An error occurred during creation of the JavaScript translation file for the language [language_name].
Drupal 6 on Windows and IIS 7.0.

A:

It sounds like a permissions issue. Is your files directory writable? Check the status page (Admin > Reports > Status report). You might also want to check out these similar issues from other Drupal users running on IIS:

http://drupal.org/node/522066#comment-1822892
http://drupal.org/node/776392#comment-2867646

