. However, Riverbed has largely replaced this with their own academic program. Check the Riverbed Community for the most current free or trial versions for students. for OPNET 16.1 or instructions on setting up environment variables OPNET Modeler - Riverbed Support
If you are a student, researcher, or professor, do not download commercial installers. Instead: Visit the Riverbed Academic Partnership page. download opnet modeler 16.1
OPNET Modeler 16.1 is strictly a 32-bit application. It will not run natively on 64-bit versions of Windows without compatibility layers, and even then, success is not guaranteed. If you are on a 64-bit system, consider using a virtual machine running Windows 7 (32-bit) instead. and even then