I have been having a very similar problem, only I am trying to make Internet
Explorer my default browser for EVERYTHING(without uninstalling MSN
Explorer). I noticed that Windows XP Pro (and probably XP Home, too) do not
list it as a browser. I believe this is what is causing me to be forced to
use it for things such as checking my email from MSN Messenger that I used
to be able to do with Internet Explorer. I think, although this is just an
assumption, that Microsoft thinks of MSN Explorer as another piece of
software, not as another browser. I think this because I have noticed that
when I check my Hotmail using MSN Explorer, it does not display the location
bar (the URL), the layout is slightly different from the Hotmail page viewed
in IE, and it has other slight differences in the interface. Good luck
solving your problem, and please let me know if you have any suggestions for
me. Thanks.