Reference > Project Configuration Settings > Publishing Options

The settings in this section control how your project is exported to Winhelp. Winhelp is now an obsolete format that should not be used for modern applications but Help & Manual still includes full support for it for backward compatibility. However, support for the 16-bit Winhelp format used in Windows 3.0 is no longer provided as this format is no longer relevant or necessary for any purposes. The 16-bit version of Winhelp is so buggy on 32-bit and 64-bit versions of Windows that it is unusable.

Since the introduction of Windows 98 HTML Help has been the standard format for help for Windows applications and it should be used for local help installed on the user's computer for all new applications. Webhelp should be used for help accessed on network drives or the Internet.

Winhelp is not supported by default in Windows Vista:

Support for Winhelp is disabled by default in Microsoft Windows Vista. Even if your applications run under Vista, any calls to Winhelp help will simply produce an error message. Support for Winhelp can be added by downloading and installing the Vista version of the Winhelp viewer from Microsoft but developers are not permitted to distribute this update with their products. It is also possible that the operating system support for Winhelp may be removed in the future. We thus strongly recommend that you start transitioning to an alternative help format as soon as possible. See here for details