There appears to be an issue when users try to download MS Word documents with IE 9 and 10 and also have recent versions of MS Office installed (not sure about earlier versions).
If the Word file is behind a password (we are working on an IIS 6 server, but the same happens with Linux and htaccess) then users received an authentication error along the lines of "Access to this website is disabled by default because it is controlled by basic authentication and does not use SSL..."
So a certificate was installed, which got rid of that error.
However now, under https - even once the user has logged in – a new login dialog box pops up every single time a new document download link is clicked. This only happens when the user chooses to 'Open' the Word document, rather than simply save the download.
Once the user has logged in initially, the other login boxes can simply be cancelled, and the document will open. But it is an annoyance for users, as they keep entering passwords and think they have mistyped and so on.
We have tried changing MIME types, so that Word is simply downloaded, to avoid the 'Open' dialog. But this doesn't work. Office still seems to recognise the Word document and offers users the 'Open' option.
The issue does not occur for Firefox, Safari or other browsers. Once the user has logged in, they simply click on the download and all is well.
Any other suggestions?