Are you talking about the Msn toolbar that comes with MSn messenger?
if you are then in Internet Explorer go to Tools (top) then select manage add-ons. Deselect the toolbar you wish to disable and then choose disable on the bottom part on that window. When you uninstall it, it should go away for good.
Word of warning about Sky e-mail, i have it and its the worst e-mail client i have ever used. Not all e-mails display properly, some give you the option to view html andsome dont so you get a nice view of html code instead of your e-mail. Get a googlemail account if you can and use that, sky blows goats.