All Interpex Software is copy protected in some way.

Shareware is protected by user name and registration code or by CPU program code and access key:

Some software is also protected in some cases by  CPU program code and access key:

The 10-character program code is generated from the computer's serial number, which is a unique signature, and the access key is provided by Interpex to unlock the software on that particular computer. This method is useful for situations where several individuals have access to the computer, for instance in a student computer lab.

Software is protected by a hardware key, which can be provided either as a USB key or a parallel port key. The USB keys are currently the most popular:

Previously supplied DOS software used a parallel key from Az-Tech, which did not require any drivers. These keys now require a driver if the software is installed and run under Windows XP. Currently supplied DOS and most windows software use the new Az-Tech "Rockey", which comes either as parallel or USB.

To install a driver for the USB or parallel port Rockey, please see Installing Az-Tech Rockeys in Windows XP