This update addresses Microsoft Security Bulletin MS04-013: Cumulative Security Update for Outlook Express (837009) for Windows XP Embedded with Service Pack 1. that includes the functionality of all the previously-released updates for Outlook Express 5.5 and Outlook Express 6. Additionally, it eliminates a new vulnerability that could allow an attacker who successfully exploited this vulnerability to access files and to take complete control of the affected system. This could occur even if Outlook Express is not used as the default e-mail reader on the system.