A new Firefox extension called 'IE Tab' was released on November 3rd for displaying those web pages that will only display properly in Internet Explorer. Unlike the 'IE View' extension that opens pages in the IE browser, IE Tab lets you view pages from within Firefox either as a Tab or in the current Window. Windows Update can now be done from within Firefox if desired.
Read about and install IE Tab from here:
http://ietab.mozdev.org/index.html
Or, if you'd prefer the Mozilla Update site,
here's the link.