I just upgraded my PC (literally last night) and the new PC has Windows 11 Pro installed. While adding all of my software back to the new PC, I encountered installer errors with SC. After HOURS of troubleshooting, I was finally able to get the game to install by using the solution at the bottom of the RSI page for Windows 11 Installation Trouble. This is the only thing that fixed my issue and I wanted to share it here to hopefully save someone else a lot of time and frustration. The fix involves editing the registry because of the way Windows 11 emulates drive sector sizes. Go here: Windows 11 Installer Fix .