.HLP File Extension
What is an HLP file?
File used by Windows Help, a program provided with Windows that lets users read help information; contains documentation and indexes for Windows programs or the Windows operating system; compiled using Microsoft Help Workshop (HCW.exe).
HLP files can be viewed with the Windows Help Viewer (WinHlp32.exe), which is provided with the Windows operating system. Older versions of help files may have trouble being viewed in newer versions of Windows.