Jiri is correct. The licence manager needs to be setup first, by the sounds of it. You can find the setup program in:
Start>All programs>SolarWinds
Run 'SolarWInds License Manager Setup'.
Once that's completed, go back to the same start menu folder to find a shortcut to 'SolarWinds License Manager'. Executing this will launch the licensing application where you can register your install & apply your license.