Microsoft is rethinking its strategy with regard to Windows Vista Help. There are no decisions to announce, but it’s possible that MAML (which they’re now calling just AML) will not ever be widely available as an authoring platform. Microsoft is currently researching how software developers can best supported in creating Help in subsequent releases of Windows.
At the Fourteenth Annual WritersUA Conference to be held in Palm Springs, California, April 9-12, 2006 the MVPs have learned that the WinHelp viewer will not be downloadable either. The WinHelp engine will not be included in Microsoft Windows Vista.
You should not count on any of your WinHelp files being viewable in Windows Vista. If everyone downloads WinHelp then Microsoft just can’t guarantee Vista’s security. Get used to the idea of no WinHelp.