[en-US]
Attention!
Follow the instructions in order. If the order is not respected,
Some Windows features may stop working.

Open "Default Programs" in Control Panel 
Click "Set program access and computer defaults"
Select "Custom" find Media Player then disable access.
Export your HKEY_CLASSES_ROOT
Open all registry files of Windows Media Player folder.
[In the HKEY_CLASSES_ROOT keys it is normal you to get error messages].
Open "Default Programs" 
Click "Set program access and computer defaults"
Select "Custom" find Media Player then Enable access.
Open your HKEY_CLASSES_ROOT.
Delete keys:
HKEY_CLASSES_ROOT\SystemFileAssociations\Audio
HKEY_CLASSES_ROOT\SystemFileAssociations\Directory.Audio
HKEY_CLASSES_ROOT\SystemFileAssociations\Directory.Video
HKEY_CLASSES_ROOT\SystemFileAssociations\Video

[pt-BR]
ATENCAO!
Siga as instrucoes por ordem. Se a ordem nao for
respeitada, alguns recursos do Windows podem parar de funcionar.

Abra "Programas Padrao" em Painel de Controle
Clique em "Definir acesso programa e programas padrao"
Selecione "custom" encontre Media Player e desative-o
Exportar o seu HKEY_CLASSES_ROOT
Abra todos os registros da pasta Windows Media Player.
[Nas chaves HKEY_CLASSES_ROOT e normal que voce obtenha mensagens de erro].
Abra "Programas Padrao"
Clique em "Definir acesso programa e programas padrao"
Selecione "custom" encontre Media Player e ative-o.
Abra o seu HKEY_CLASSES_ROOT.
Exclua as chaves:
HKEY_CLASSES_ROOT\SystemFileAssociations\Audio
HKEY_CLASSES_ROOT\SystemFileAssociations\Directory.Audio
HKEY_CLASSES_ROOT\SystemFileAssociations\Directory.Video
HKEY_CLASSES_ROOT\SystemFileAssociations\Video