go to the nebula folder on the harddrive (where you found your ser-file). copy (overwrite existing one) init.n2p into the programs-folder and init.n2v into the vector-folder. then make a backup-copy of the files that were sent to you. the license is written in those files and as long as your machine doesn't change (hardware) it should work.
system 1: windows 8 32 bit - samplitude prox, tracktion6, reaper system 2: mac osx yosemite - reaper(32+64bit), tracktion6(32+64bit)
both systems on: macbook pro (late 2009), core 2 duo 3,06 ghz, 4 gb ram, graphic: nvidia geforce 9600M GT 512 MB