Thanks. Following is what one of the people with the problem had to say
Apparently that wasn't the nature of her difficulty. I'm trying to think if there is some kind of Outlook-promoting mini-application that can be uninstalled, if it isn't a setting within Outlook?

This is what I find when I select Tools in Internet Explorer:
Tools>Internet Options>Programs

There is no option listed as "Set Programs", but there is a list where you can specify which program Windows automatically uses for each Internet service: HTML Editor, E-mail, Newsgroups, etc. I already have Outlook Express selected as the default program for my e-mail , so I have no idea why Outlook is trying to barge in. I thought that maybe since I still have Internet Explorer 6 on this computer it would help if I upgraded to a newer version, but I don't think it would make any difference - I have IE 7 on my laptop, and I get the same drop down menu there as I do on my desktop with IE 6.

And in any case, why would this other person who emailed me be having trouble with MSN?