BuddyPress.org

Change permalinks structure in admin to something else and save and see what happens.

index.php-style permalinks, usually found on some IIS installations but not all, do not work with BuddyPress out of the box. One option is to figure out a way to automatically prefix all incoming URLs with index.php that don’t have them already, perhaps in the equivalent of a .htaccess file. However, I’ve not had to sort this out before and I don’t have any experience with IIS.

In IIS Manager, go to the virtual directory and click right / properties, there you can go to the documents tabs and set up the “enable default content page” to index.php

IMHO Apache runs circles around IIS, on our win2k8 server we’re running apache and php instead.

This article might also help you translate .htaccess to an IIS webconfig, too (if needed) :http://learn.iis.net/page.aspx/557/translate-htaccess-content-to-iis-webconfig/

As an M$ engineer IIS is not something I would rather rely on for production sites unless you have M$’s budget to just throw more servers at the load and be able to deal with a few coming off the rails while you sort things out (yes even in IIS7). That’s why I’m a LAMP (Linux, Apache, MySQL and PHP) admin when it comes to things I own and care about.

If you’re not planning to be working with ASP or need active directory integration with desktop PCs, and that sort of thing there’s no need for it. I say let WordPress run on it’s native environment.