Enable Firefox to Open Local Files Linked From an Intranet Website

Often an Intranet website will have links that reference files (such as Word documents, PDFs, Excel spreed sheets) located on mapped network drives (such as file://N:/share/myword.doc). In Internet Explorer, clicking on such links will download the referenced file to the client and open it. Unfortunately, this does not work in Firefox without some manual configuration. My understanding is Firefox has disabled this feature by default to prevent malicious web sites from trying to link to and open files in your local directories (a security policy that Internet Explorer choose to ignore).

You can configure Firefox to download and open files linked from explicitly specified websites to the client's local drive (and mapped drives) by adding the following to the file user.js (create this file if it doesn't exist) in Firefox's profile directory (which should be something like: C:\Documents and Settings\Caleb\Application Data\Mozilla\Firefox\Profiles\abcde123.default, where abcde123 could be any sequence of characters):

user_pref("capability.policy.policynames", "localfilelinks");
user_pref("capability.policy.localfilelinks.sites",
   "http://web.intranet.com");
user_pref("capability.policy.localfilelinks.checkloaduri.enabled",
   "allAccess");

You can specify more than one web site by separating each address with a space. For example, to add both http://web.intranet.com and http://web, use:

user_pref("capability.policy.policynames", "localfilelinks");
user_pref("capability.policy.localfilelinks.sites",
   "http://web.intranet.com http://web");
user_pref("capability.policy.localfilelinks.checkloaduri.enabled",
   "allAccess");

I'm using Firefox 3.0, but I believe the above is true for all versions of Firefox greater than 1.5.