You state that you have removed and reinstalled WMP twice; this is only possible if you have acquired version 10 as an update or a download, and even then, it is sometimes not present in the list of installed updates (a well known and so far neglected bug).
So have you got ver10 as an update from Windows Update? Or is your operating system revision recent enough to include ver10 as standard? Is ver10 listed among your installed updates? Look in "Change or Remove Programs".
If it is included in the build, the closest that you can come to removing it is to deselect it from "Add/Remove Windows Components". But... deselecting any Windows component does not uninstall it, but only removes access to it and all references to it. When you come to select it again, no files are changed.
Even manually downloading ver10 and attempting to overwrite the current installation will achieve nothing; if ver10 is already present, you will be told that you already have it and the installation process will stop.