You can put this in your ~/.bashrc or the equivalent file to make it persistent.
On Windows
To allow DLL detection for all users, it needs to be added to the system PATH variable. For this, follow the steps:
Open Advanced System Settings:
Windows 8: Move the Mouse pointer to the bottom right corner of the screen, Right click, choose System. Then click "Advanced System Settings"
Windows 7: Open the Start Menu and Right Click on "Computer". Then choose Properties and click "Advanced System Settings"
In Advanced System Settings window, click on Advanced tab
Click on Environment Variables, then under System Variables, find PATH, and click on it.
In edit mode, append %AF_PATH%\lib. NOTE: Ensure that there is a semi-colon separating %AF_PATH%\lib from any existing content (e.g. EXISTING_PATHS;%AF_PATH%\lib;) otherwise other software may not function correctly.
If using CUDA, append %CUDA_PATH%\nvvm\bin to the PATH as mentioned above.