Thanks to you and Timesurfer for answering my question,the reason Iasked this question is because I have seen in the past people asking for a SLP Key for a certain Brand or PC and also asking or a cert as well and I just was not sure I figured DAZ's Loader had the cert's already installed and choose's the proper one.
It has certificates and reads serial from a .ini file so no need to get your own ofcourse. You can if you want do it manually with slmgr command.