For Siemens TIA Portal V13 SP1 Update 4, the most authoritative "paper" or documentation is the official Siemens Industry Support portal. However, if you are looking for stability and performance in 2021 or later, technical experts generally recommend moving to Service Pack 2 (SP2) or later for better compatibility with modern operating systems like Windows 10. Key Documentation and Resources
If you start a project in V13 in 2021 and later need to upgrade to V17 or V18: siemens tia portal v13 sp1 update 4 better 2021
: If TIA Portal is already installed, use the integrated "Automation Software Updater" tool to find and download the latest available updates. Siemens SiePortal direct download links For Siemens TIA Portal V13 SP1 Update 4
Official Updates & Download Page: The primary source for downloading and reviewing the changes in Updates for STEP 7 V13 SP1 and WinCC V13 SP1 covers all fixes and improvements. Overall rating: 4
The Fix: Siemens released TIA Portal V13 SP2 specifically to provide official Windows 10 support.