As usual, help PLEASE/adobe premiere wont display playback

Hello!
I’ve just started using premiere pro cs6 on my brand new computer (i7 3537u, 8gb RAM, 1TB HD, GeForce 610m).
Basically first time i’m using Premiere and it won’t play any type of video file in the playback window (upper right one, not sure how it’s called actually). I can hear sound and everything else seems to be working fine, i can edit, drag, render and play the clips in the project window. It just shows grey in the playback window.
I’ve tried mov, avi and mp4 files and none works.
reinstalled and still not working.
Asked a friend to try and play the clips in the exact same version of premiere and he did succeed.
At this point i’m just desperate since i know so little about premiere I can barely search google effectively.
A picture of my screen to make things as clear as possible:

Untitled.jpg

Will very much appreciate your help!

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via Video Editing Forums: Digital Director – Adobe Premiere, Premiere Elements, and After Effects http://www.videoforums.co.uk/threads/46568-As-usual-help-PLEASE-adobe-premiere-wont-display-playback?goto=newpost