Some times I had problems when disconnected my external HD using Windows’ s Removal Device Assistant, the most frequently was “This device is currently in use. Close any programs or windows that…”. This message appeared even with all programs closed.

After checked Windows settings, process and services, I noticed that the problem was in service “Windows Media Player Network Sharing Service”, forcing me to stop it before remove the device.

But still, this solution not is right, then I found the most right:

The service “Windows Media Player Network Sharing Service” is responsible to share your media files (musics and videos) in your network or in the internet (like your name sounded. 🙂 ). This is default setting in Windows 7, to disable it…

Click in Start menu, type “Network and sharing center” and select the application. Like show in the image

Click “Choose homegroup and sharing options”

Clique na opção “Escolher opções de grupo doméstico e de compartilhamento”

Now click on “Choose media streaming options…”

Change option of item “Media programs on this PC and remote conections…” to “Blocked”.

Finish! From now you can remove your external hard drive or other removable storage devices without problems.