http://bugs.winehq.org/show_bug.cgi?id=25502
--- Comment #2 from A Wine user RandomAccountName@mail.com 2010-12-16 10:25:07 CST --- (In reply to comment #1)
You'll need to disable / remove that somehow to install Internet Explorer itself.
That's what iexplore -unregserver does (basically). You also need to remove some DLLs and set overrides for them if you actually want to use IE, but it's not necessary just to see this bug.
Are you sure you see the same error? The error I'm talking about happens after the installer spends some time installing various things, and explicitly lists which components failed to install. Trying to run the installer in a brand new prefix gives me a generic failure before anything can be installed.