Windows Mobile 5.1

Windows Mobile 5.1 is an updated version of Windows Mobile released on October 25, 2006. 2 months after the release, it was caught in the 2007 disaster bug.

2007 bug
This is the first Windows to receive the 2007 bug, alongside Microsoft Five Embedded, Windows 5.1, and Windows Mobile 4.1. Unlike the Microsoft Five Embedded or Windows Mobile 4.1, however (with Windows 5.1), it will get supported again once the phone is updated.
 * See also 2007 disaster bug patch

Updates

 * 5.11: November 17, 2006 - added Windows Vista app icon updates (except Internet Explorer, where that was updated from start).
 * 5.12: December 12, 2006 - Bug fixes
 * 5.13: January 16, 2007 - Fixed bugs from the 2007 disaster bug patch.
 * 5.14: June 5, 2007 - Fixed bugs and speed improvements
 * 5.15: August 7, 2007 - New folder manager
 * 5.16: October 1, 2007 - Fixed bugs
 * 5.17: December 4, 2007 - Enchanted speed
 * 5.18: March 21, 2008 - Fixed bugs
 * 5.19: May 2, 2008 - Fixed bugs and enchanted speed