Windows: If you've installed older software in Windows 7, you might notice that .hlp-formatted Help files aren't recognised or supported. Microsoft offers a free download to read and manage those WinHelp files.
Windows 7 come with their own Help and support systems, so this is just a compatibility update for anyone needing to look through older .hlp files on a newer Windows system. You'll have to run a "Genuine Windows Advantage" check before you can download, but once that awesome little bit of corporate security is over, the WinHelp reader quietly installs, opening whenever you open a .hlp-formatted Help file.
Windows Help for Windows 7 is a free download for, um, Windows systems only.