"ABC Amber HLP Converter is a useful tool that allows you to create printable, manual-quality documents from Microsoft Windows Help files. The program converts hlp files to any document (and database) format you wish - PDF, RTF, HTML, DOC, CHM, TXT, DBF, XML, CSV, XLS, MDB, etc."
"With the demo version of the program, you may test it free of charge for 30 days. If you want to continue to use it after the 30 days, you must register the program. Note that the demo version doe not support batch conversion, etc. After purchasing the program [the authors will] send you the fully functional and LATEST version (v3.01) with no restrictions."