If it's been more than a week since you installed or made changes to Windows Media Player, you should use other methods to restore the default settings. In Windows XP, Windows Vista and Windows 7, Windows Media Player is included as a feature of your operating system. If you're running Windows XP and you have installed a newer version of Windows Media Player than the one that came with your operating system, you can roll it back to the previous version, then reinstall the newer version to restore the default settings.
To roll back Windows Media Player in Windows XP, click "Start," "Control Panel" and then "Add or Remove Programs." Roll down to Windows Media Player in the list, then click "Remove." After the rollback is complete, reinstall the newer version of Windows Media Player.
In Windows XP, Vista and Windows 7, you can create a new user account, then delete the old account to restore the default settings in Windows Media Player. Click the Start button and select "Control Panel." Under "User Accounts and Family Safety," select "Add or Remove User Accounts." Click "Create a New Account." Type a new account name and the account type. Log in to your new account and set it up with the same settings as your old account. When you're confident that your new account has everything you need, delete the old account and rename the new account with the same name as the old one.
For more information about this software, read Top Free Plugins for Windows Media Player.