Setting the setup.exe to "Windows 7 Compatibility Mode" is essential. This fools the installer into believing it is operating within its native environment, preventing immediate "OS not supported" errors.
During the final stages, CATIA sets up "Environment Variables" for its licensing and settings (CATEnv). On Windows 11, these files are often written to the ProgramData folder. It is crucial to ensure the user has full read/write permissions to this directory, or the software will fail to launch after a "successful" install. Post-Installation and Graphics Optimization install+catia+v5+r21+on+windows+11+updated
and disable "3D Accuracy" or adjust the "Anti-aliasing" settings. Missing MSVCR100.dll: The Ultimate Guide: How to Install CATIA V5