When you have a question about a computer application you may click a "Help" button causing a Help window to appear. Two of the most common help formats are HLP, also called WinHelp, and CHM which stands for Compiled HTML Help. The help file you see and the features it provides depend on several factors.
Help Files
- Software distributors do not have to use Windows-based HLP and CHM files. They could simply add their help to regular text files. However, by using one of these formats, they can create richer help displays for their users that include formatted text, graphics and advanced navigation systems. HLP files have ".hlp" file extensions and use old technology dating back to Windows 3.1. If your operating system is Windows XP, you may see a help window using the older HLP program. You will not find this type of help in newer Windows versions, however, because Microsoft replaced HLP with CHM when it introduced Windows Vista.
HLP
- The HLP help format may be old, but some programs still use it. Applications such as Visual Studio still have the ability to create these types of files. If you ever receive an error message after clicking an application's "Help" button, HLP may be the problem. An error occurs when you upgrade to Vista or Windows 7 and attempt to run an old program that uses the HLP format. You may also get an error message in Vista or Windows 7 after installing an old program that uses HLP. Remedy the problem by installing the free WinHlp32 program provided by Microsoft on its 3a Web page. You will then be able to view old HLP files in Vista or Windows 7.
CHM
- Modern applications use the newer CHM format to display help. CHM help systems have the ability to run independently of an application. This allows you to double-click a CHM file and view help without launching its associated application. CHM windows contain two panels. The right panel displays the help contents and the left panel contains a Table of Contents that can also display search results. A "Search" button allows you to generate those results after entering a search term into a text box.
Working with CHMs
- As the name suggests, HTML Compiled Help files consist of HTML. If you use Microsoft's HTML Help Workshop, you can build help pages as HTML files and use the program to convert them into a CHM file. Microsoft's Help Workshop on Microsoft's HTML Help Workshop and Documentation Web page contains the installation files you need. If you ever need to convert an existing CHM file into separate HTML pages, you can download CHM-to-HTML conversion programs that perform that task.
