This is what I had previously posted to the Gigabyte support :
Previously using a single monitor on the top DVI plug had no issues however, when replacing with a new monitor using an HDMI connection I turned off the PC, unplugged the DVI connection and plugged in the HDMI connection, turned the pc power back on and the new HDMI monitor worked without any issues. I quickly realised I wanted to re add the old DVI monitor as a secondary monitor so I turned the pc power off and reconnected the DVI monitor and left the HDMI connected as a main monitor and had no issues the first time it was turned on. After restarting however I lost any display from any of the ports. I have tried many solutions from using different monitors, wires, PCI-e 2.0 slots reset my bios and even removed the video card completely and turned on the computer to let it run and hopefully reset the settings when re entering the video card. I continue to have no video through any of the ports. even tho the BIOS does not make any beeps signaling that it reads the video card properly. Both monitors have been checked using another computer and work fine.
motherboard : Gigabyte G1 Assassin 2
BIOS ver. : f11
Windows 7 64x