I am working on an online education website that frequently uses pop up windows. This is part of a learning management system from a third party provider so not possible to
There seems to be some discussions around this over on "webmaster world", the solutions provided look something like this: http://www.webmasterworld.com/forum80/704.htm
They seem to be saying that the classid you need to use is a bit of a moving target for different versions of the toolbar, to say nothing of any of the other toolbars and wacky things that people may have installed. As someone who works with elearning content and LMSs the idea of detecting all of the things that have got in the way over the years gives me a headache. Especially if I was using a 3rd party LMS so can't really fix it "once" on the server and would have to repackage the content each time a new version of toolbar X came out.
Also it seems various toolbars will appear in browser user agent strings, but if you are needing a javascript/client-side solution that might be out: eg http://www.zytrax.com/tech/web/firefox-history.html