Problem loading XPS documents

I'm encountering problems when trying to open XPS documents. Although XPS
documents on my computer are associated properly with the Microsoft XPS
Viewer, they load in Mozilla Firefox, my default browser. Obviously, the
documents won't open in Firefox. XPS documents are designed to open in an
Internet Explorer window but, apparently, when the default browser is
switched from IE, the XPS documents will no longer open in IE, even when IE
is loaded.
The only workaround I've found is to open IE and then load the XPS document
through IE's File > Open command. I would prefer to open XPS documents in
the normal way by clicking them. Is there a way to do this without switching default browsers?

Solution :

Yeah, the MS devs working on this weren't too bright. Go to Control
Panel\Default Programs\Associate..., choose .xps, click Broswe and
broswe to Internet Explorer (on x64 editions, be sure to select x86
version). Now, the first time you click an xps link in IE it may
fail, but clicking Reload should make it work from now on. Firefox
will now work too.