If you installed the Media Player 9 beta, this is expected behavior.

If you set HKEY_CURRENT_USER\ControlPanel\Desktop\PaintDesktopVersion, to 0, the text is still there.

If you must remove it, delete the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\CA\Certificates\FEE449EE0E3965A5246F000E87FDE2A065FD89D4

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\ROOT\Certificates\2BD63D28D7BCD0E251195AEB519243C13142EBC3