MSN was an online service initially provided by Microsoft back around the time of Windows 95. It's been included for some reason on every version of Windows through Vista, but it's a white elephant. Nowadays MSN is just a portal, like Yahoo or AOL, rather than a service. The MSN application in previous versions of Windows were mainly just a different browser, tailored to the MSN portal, but it's something I always uninstall whenever deploying a new machine or configuring a new image.
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