PowerZip requires the following external programs to work with Arj, Ha and LZH archives:

ARJ files are manipulated by the ARJ 2.50 program from ARJ Software, P.O. Box 249, Norwood, Massachusetts 02062. You can also download it from http://www.akc.com/arj250a.exe. Please note that ARJ is shareware, not freeware. For more information, please see ARJ's license agreement.

LZH files are manipulated by LHA 2.55E program from Haruyasu Yoshizaki. LHA is freeware. You can download LHA from http://wcarchive.cdrom.com/pub/simtelnet/msdos/arcers/lha255e.exe

HA files are manipulated by HA.EXE program by Harri Hirvola. HA is public domain. You can download it from http://sources.codenet.ru/files/formtfil/h-m/ha0999c.zip

After downloading the programs, please install them, and specify the path in the Program Locations tab of the Settings dialog box (File -> Settings). You will then be able to use PowerZip to open, extract and create archives of the above types.