OE error

[Chupa]

Well, I just got off the phone with my parents, and the computer problem o' the week for them is that whenever they load Outlook Express, it says it cannot find "msoeres.dll." I guided my dad through the process of installing IE 6 because I thought maybe it would rewrite the file, but if gave an error saying that file could not be found.
What would be the easiest way to fix this?

Thanks