Windows Media Player (WMP) 12 in Windows 7 lets you preview and listen your songs or tracks automatically on mouse hover. The playing stops as soon you lift off the mouse cursor.
To enable this, open Windows Media Player 12, click Tools and then Options on the menu bar:
in the Options window, go to Library Tab :
Now, check the box (where we have placed the cursor in the above sceenshot) where the text beside it saying “Automatically preview songs on track title hover” under Media Library Settings. Click Apply and then OK.
Now, go to songs list under Windows Media Player Library, hover over any song’s title and you will be able to have preview (actually pre-hear!) of the song: