The most reliable way to get STEP 7 is through the official portal.
SIMATIC STEP 7 V5.5 SP2 is legacy industrial automation software used to configure and program SIMATIC S7-300 and S7-400 controllers. While newer versions like STEP 7 V5.7 simatic step 7 v5 5 sp2 download fixed work
To ensure the software runs without errors (the "fixed work" state), follow these compatibility guidelines: Step7 5,5 sp2 free download - SiePortal - Siemens 9 Mar 2012 — The most reliable way to get STEP 7