Ok, after a few calls, I got a registration code. I put it in and it says it is registered to me.
So I guess that is all I will ever need ?
Yep. You're golden.
When you did that, JRiver will have emailed you a MJR file. If you have other copies of Windows on other computers, you can copy this MJR file over to them and use it to license additional copies of MC. You're allowed to use a single license of MC on all of the computers of a particular platform (Windows, Mac OSX, and Linux licenses are separate if you don't have a Master License) that you own personally (within reason). Obviously if you're using it for a business the separate physical users need their own licenses, but for a regular "home user" with a server, HTPC, and laptop or whatever, you're cool with one. The MJR files "last" for 14 days, after which they expire. But, you can make a new one if needed via the same mechanism you used to get this one going.
What you did, to add a license to that original copy of MC (where you got the MJR file emailed to you) is called a "Restore". You're automatically allowed 10 of these per year (rolling, not calendar), though if you ever run out, you can just tell us here, and someone from JRiver will come along and fix it, assuming you're not up to no good.