The context-sensitive online Help (.HLP) file must be a standard Windows Help file. It is written in Rich Text Format and compiled into WINHELP format. The first page in this file should be a contents page, and it should contain a page for each context-sensitive Help message required. When the user presses the Help button in a dialog box, the Setup Engine calls WINHELP with the script's Help file and the HelpContext identifier. See the existing .INF scripts for examples.