Rockwell Automation doesn't officially offer "portable" versions of RSLinx. The software is designed to install deep-level drivers and services (like the Harmony service) that manage your PC's COM ports and Ethernet stacks. A true "portable" version often fails because it can't register the administrative-level drivers needed to actually see the hardware. The "Happy Ending" Solution

: You will need a free Rockwell Automation account to complete the download.

This article guides you toward solutions – including how to obtain RSLinx Classic Lite 2.59 legitimately, why you might not need it, and how to use modern free alternatives.