OK,
It looks like the initial Media Center process is hung or not responding for some reason. When you try to start a second Media Center instance, you are probably getting the message that is caused by two instances running at the same time.
There is no obvious cause for your problem. You need to eliminate possible causes.
I suggest you perform a test to see if there is a problem with your current media library:
- Use Task Manager to end the hung process (so that there areno Media Center processes listed in Task Manager).
- Start Media Center again but do not try to play anything
- Create a new Media Center library using the Media Center Library Manager.
- Add some music to this library and try to play it.
- Try to play the music added to this new library
If you are using an external DAC, you could test Media Center through your computer's internal speakers (if there are any!). This would involve reconfiguring Media Center to use a different audio device.