Disable "Hardware Acceleration" in your GPU settings or launch CATIA and go to Tools > Options > General > Display > Performance and lower the 3D Accuracy.
The most common reason CATIA V5 R21 fails to install on Windows 10 or 11 is that the installer checks the Operating System name and stops because it doesn't recognize "Windows 11." install catia v5 r21 on windows 11 fixed
| Component | Official R21 Requirement | Windows 11 Actual Need | | :--- | :--- | :--- | | OS Build | Windows 7 / XP | Windows 11 22H2, 23H2, or 24H2 | | Architecture | 64-bit (native) | x64 | | .NET Framework | 3.5 SP1 | 3.5 SP1 + 4.8.x | | Internet Explorer | IE 8 or 9 (required for help/docs) | IE mode in Edge + registry fix | | Graphics | OpenGL 2.1 | OpenGL 4.6 (backward compatible) | Disable "Hardware Acceleration" in your GPU settings or
If CATIA won't open or throws errors after installation, apply these fixes: apply these fixes: