Windows Live Messenger

Windows Live Messenger, previously known as MSN Messenger, was an instant messaging client introduced by Microsoft in 1999, before being shut down in 2014.

Backgrounds
[todo: table] Chat window backgrounds were added in MSN Messenger 6.1. All five were licensed from Getty Images.

Animated backgrounds
Animated backgrounds were added in MSN Messenger ?.?. [todo]

MSN/Windows Live Messenger 6.1 to 8.5
Display pictures were introduced in version 6.1. Most of these are higher res versions of ones that appear in Windows XP, except for Soccer Ball which is unrelated to XP's ball user account picture.

Windows Live Messenger 2009
[todo: table] 2009 added many new display pictures. Most of these were also used in Windows Vista, although a few were specifically designed for it. The previous display pictures remained.

Windows Live Messenger 2011 and 2012
[todo: table] At this point, most of the pre-2009 display pictures were removed, along with the buddy ones from 2009. A few new flat ones were added.