No preview sound in Media Bay but can hear it after draggin

Hi all. New here. I have Cubase 6 64 b and 32 b installed. Win 7 16 gb ram 6 core amd.
The problem:
When i click on a sound in the media bay i dont hear anything and i tried in both 64b and 32b vers but its the same.
I do hear sound when i click play to play the track and i do hear sound after im dragging the sound from the media bay to the track and play it. BUT no preview sound on the media bay.
Do i need to do something in the settings maybe in cubase or in the media bay.
Please if you can help me will be great
Thank You

Hello,

This is problem of settings in the VST Connections. Open it, find Studio tab, and Add Channel Monitor 1. Choose your main output here.

Best

Thank you