Obtain the self-extracting .exe file (e.g., SIMATIC_Automation_Tool_V4_0_SP3_UPD1.exe ) from the Siemens Industry Online Support (SIOS) website.
To ensure stable operation of the SIMATIC Automation Tool on a 64-bit Windows system: SIMATIC S7-1200 Basic Controllers - hocom.tw S7 1200 Tool 64 Bit 40