Hold on tight!
Failing to meet prerequisites will halt the installation. Before downloading, verify your environment based on the official Readme V9.1 :
Before downloading and installing PCS 7 V9.1, verify that your engineering stations (ES) and operator stations (OS) meet the necessary hardware and operating system specifications. Hardware Prerequisites Intel Core i7 or Xeon (minimum 4 cores). simatic pcs 7 v91 download new
This version expands support for the ET 200SP HA modules, enabling higher density I/O configurations that save significant control cabinet space. Failing to meet prerequisites will halt the installation