I completely understand your frustration on this situation but let me help you as much as possible.
I see you have done several troubleshooting steps but I would like to verify some more information about your system so, can you please post your dxdiag report here?
for others - i have changed the lcd monitor to a different one with HDMI port.
also changed the cable - HDMI to HDMI.
its now working fine .
seems like the intel graphics card has issues with the signal coming from DVI, so use HDMI instead.
Thank you for sharing the details with us. I am sure this will be very helpful for other customers facing the same problem.