HQX files are binary files, such as images or music files, which have been converted using the BinHex program to send them as ASCII files via email. These so-called BinHex encoded files are larger than the original, but have the advantage of combining both "forks" of the Mac OS file system in an archive and less prone to file transfer problems.
Hqx was used very often up to Mac OS 9, on Mac OSX there are better alternatives with eg dmg or zip. In addition, fault tolerance in data transmission no longer plays such an important role today. Until Mac OS 9, HQX files should be automatically opened by the default installed StuffIt Expander, as of Mac OSX an additional program must be installed.
Although the HQX format is not used under Windows, with the StuffIt Expander there are of course possibilities to open these files.
Most often resolving problems with opening HQX files is very simple. Just install an appropriate program that supports such files. All of the listed programs support HQX files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of HQX files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate HQX files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the iArchiver applications is not on the list, select "Browse" option in order to manually locate the directory where iArchiver has been installed.
Sometimes problems with opening HQX files may not lie with the application itself, but can arise due to other causes, such as: