The CHW file extension is assigned to a group of individual help files. CHW files are exclusively used by the Microsoft corporation, and are responsible for creating a table of contents for a user's help center articles. CHW files must stay up to date in order for the Windows Help application to be able to pull the appropriate help articles.
Help Files
- Windows compiles help files in HTML format, giving them the file extension CHM. These files were first developed by Microsoft in 1997 and continue to be the standard for the Microsoft Windows operating system as of the Windows 7 version. Help files are indexed, so that when a user calls upon a particular article it can be located and loaded more quickly. A group of CHM files is assigned the file extension CHW.
Merged Files
- When a group of CHM help files are merged, Windows automatically generates a CHW file. The Windows user does not need to manually create these files, and in fact most users likely don't even know they exist. When one of the individual CHM files in the CHW file is altered, the CHW file is regenerated to include the changes.
CHW Contents
- The CHW file in Windows Help contains the help center's table of contents. The CHM files are merged within the CHW in such a way that a reference is created for each individual CHM file. Because a reference exists, an individual file from the CHW can be accessed quickly by a user.
Opening CHW Files
- A CHW file cannot be opened on a Mac device, as the file is Windows-based. A PC user can access a CHW file via Microsoft Help, Help File Explorer or HTML Help Utilities. The files may also be compressed, meaning that the size is reduced, using a program called KeyCHW. The file itself should not be altered, however, or the Windows table of contents will not function.
