"Annoyances.org, which lists various aspects of Windows that
are, well, annoying, says "this update adds to Firefox one of the
most dangerous vulnerabilities present in all versions of Internet
Explorer: the ability for Web sites to easily and quietly install
software on your PC." I'm not sure I'd put things in quite such
dire terms, but I'm fairly confident that a decent number of
Firefox for Windows users are rabidly anti-Internet Explorer, and
would take umbrage at the very notion of Redmond monkeying with the
browser in any way.
"Big deal, you say? I can just uninstall the add-on via
Firefox's handy Add-ons interface, right? Not so fast. The trouble
is, Microsoft has disabled the "uninstall" button on the extension.
What's more, Microsoft tells us that the only way to get rid of
this thing is to modify the Windows registry, an exercise that --
if done imprecisely -- can cause Windows systems to fail to boot
up."