After installation, you can activate NI Multisim 14.3 using the following methods:
Ensure your serial number is for version 14.3. A version 14.0 key may not work for 14.3. how to activate ni multisim 14.3
A valid (found on your purchase receipt or NI user account). An active NI User Account . An internet connection for instant activation. After installation, you can activate NI Multisim 14