Windows Live replaced MSN Messenger. MSN was one of the first live messaging services. It was the popular messaging service for a decade, but in 2005, MSN wanted to rebrand. They chose to rebrand and do a name change with that is now called Windows Live. The later is still used today. It has many updated features, such as the ability to chat through XBOX and use on certain mobile phones like the S60. MSN Messenger can still be used today, but it has not been updated since the rebrand in 2005. Despite that, many people still prefer to use MSN Messenger today.
MSN Messenger is Microsoft’s messenger application, which is included in the Microsoft Network’s list of services, one of which is Hotmail. Microsoft chose to rebrand MSN and go with the name Windows Live Messenger. Some people even now prefer to use MSN messenger as opposed to Windows.
This preference is because MSN messenger is easier and more transparent compared to Windows Live Messenger. People who utilize this service only for messaging typically are the ones who use this service.
However, Windows adds essential features that are not available in MSN, including integration as well as other platforms. Between the two of these, it is a tradeoff between whichever you cannot go without simplicity and convenience or advanced features.