Used IE4RC for Windows?
Developer’s Description
IE4RC means Internet Explorer extension for RemoteCalendars. It's a .NET plug-in for Internet Explorer, and it will make it possible to subscribe an iCalendar (RFC 2445) in Outlook if RemoteCalendars is installed.
Version 2.0 adds support to the webcall protocol: if you click on a webcall URL, the iCalendar will be directly subscribed into Microsoft Outlook through RemoteCalendars.
