Mshtml.dll is at the heart of Internet Explorer and takes care of its HTML and Cascading Style Sheets (CSS) parsing and rendering functionality. Mshtml.dll exposes interfaces that enable you to host it as an active document. Other applications such as Microsoft Word, Microsoft Excel, Microsoft Visio, and many non-Microsoft applications also expose active document interfaces so they can be hosted by shdocvw.dll. For example, when a user browses from an HTML page to a Word document, mshtml.dll is
This is a Windows file installed with the operating system and protected with Windows File Protection (WFP).