Please see the article at http://software.intel.com/en-us/articles/find-my-serial-number/.
If you have not registered the product, please contact your reseller with the purchase order number and they can provide you the associated serial number.
License checkout for 2016 and newer product versions is very slow compared to the 2015 version on machines with remote access to the floating license server.
A "named user license" (single user license) does not use a license server manager, and only requires a local license file. Only floating licenses and node locked licenses need a