If you downloaded the game via a platform like Steam:
This file is not a standard Windows system file (like kernel32.dll ), but rather a third-party library required by specific applications to function correctly. When this file is missing or corrupted, the dependent software will fail to launch, resulting in error messages such as "The program can't start because rui-41.dll is missing from your computer."
If you are sure the error is related to (Indeo Video), you may need to install or register the codec.