Here is some encouraging news from Microsoft Corporation.
<quote>
Users who want to view 32-bit .hlp files must download the program from the Microsoft Download Center, and then install it on their computers. The download for Windows Help is still in development. It will be available in time for the consumer release of Windows Vista scheduled for early 2007.
</quote>
Windows Help program (WinHlp32.exe) is no longer included with Windows:
Windows Help program (WinHlp32.exe) is no longer included with Windows
© 2006 Microsoft Corporation. All rights reserved.
As for the converters, I haven't tried any. But see if you can find anything useful in the following site:
Shareware downloads Web Authoring - HTML Help Authoring at SnapFiles.com:
Shareware downloads Web Authoring - HTML Help Authoring at SnapFiles.com