Well, after some fiddling, I don't think you can change the actual location of this Library. You can change what is included in it. And if you use Windows Media Player to record your shows, I'm pretty sure you can change the default saved location
So, if you wanted to save your shows in this folder:
C:\Users\Derek and Tiena\My Recorded TV
simply include this folder in the Public Recorded TV Library, and whenever you click the Recorded TV link in the Start Menu, it will be as if you are actually in that folder (C:\Users\Derek and Tiena\My Recorded TV) and you will be able to see all the things you saved in it. The files are not actually in the Library, they are just "included" there. That's the dynamic of Libraries in Windows 7.
I'm not sure if that satisfies what you were trying to do, but I don't really have any other options. Like I said, you can't change the location of that Library (the one accessed from the Start Menu).
You can make a Library in the left pane called "My Recorded TV", and all you have to do is simply include the same folder that you did in the Public one and the same effect will be achieved. I know it seems like a round-about way of doing things, but I really don't know any other way. You will be able to access those files the same whether you go through the Start Menu or through the Library list in the left pane. See what I mean?
Is this anywhere close to solving your problem? I'm pretty sure it wasn't what you were expecting, but, then again, it wasn't what I was expecting either.