Microsoft will be making some necessary changes to Microsoft Windows desktop operating system software related to the way in which Internet Explorer handles some web pages. The purpose of this communication is to provide additional information on the planned IE ActiveX update for Windows® client and server, discuss the optional Compatibility Patch intended to provide Enterprise customers additional time to prepare for the update, and to point organizations and website developers to relevant technical information. These changes are related to Internet Explorer and the Eolas Technologies and the Regents of the University of California v. Microsoft patent case (Eolas v. Microsoft). The IE ActiveX update will be rolled-up and included in the next available Internet Explorer security update, which could come as soon as the April 2006 Bulletin release. This update will be High Priority via Windows Update and Automatic Update. An optional Compatibility patch will be made available the same day as the IE ActiveX update via the Microsoft Download Center.