To get the latest version of WMP, you can just use Windows Update. I don't know whether WMP 11.0.6000.7000 exists or not.

To get older version of WMP, see the following thread:
How to roll back or uninstall Windows Media Player 11 (Windows Vista)

If you downgrade WMP, you will lose all your licenses. Make sure you can re-acquire them. You should also disable automatic Windows updates. And you should also know that some content providers force you to upgrade WMP.