.CHW File

File extension chw is related to Microsoft Help and used for files that contain help general index.

Microsoft Compiled HTML Help is a proprietary format for online help files, developed by Microsoft and first released in 1997 as a successor to the Microsoft WinHelp format.

It was first introduced with the release of Windows 98, and is still supported and distributed through Windows XP, Vista and Windows 7 platforms.

Files with chw extension can be most often found as files saved in Microsoft Help HTML general index file format. Used in Windows Help since 1997.

How to open:

Most of index files are not meant to be opened directly and only serve for indexing purposes.

How to convert:

It seems that there exist no way how to convert .chw help general index files to other file formats. However, some help files management programs can be used to handle .chw files.