Windows Me build 2509

Windows Me build 2509 is a beta 3 build of Windows Me. It is very similar to the previous builds. MSN Messenger has been updated from version 2.1 to 2.2.

Neptune reference
A file named, with the version number 5.50.5117.1 was found in this Windows Me build, but it is unknown whether this Neptune build ever existed.

Some speculate this would've been a Milestone 2 build. It would've been compiled someday after 11 December 1999, meaning it would be one of the last Neptune builds before the Neptune project was canceled in January 2000.