MSN Messanger comes with XP Pro as a component. To remove it, go to Control Panel> Add/Remove Programs, then on the left panel click at Add/Remove Windows components. Uncheck the last item.
BTW, were you not able to 'overwrite' the old 4.7 with the new 6.0 when you installed the new version ?
I'm using XP pro. MSN Messenger 4.7 included in there. But I want MSN 6.0 (or the latest) and I already install it. How can I uninstall MSN Messenger 4.7 in XP Pro

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