Hi,
So just to clarify, what ports do you have available on the GPU and on the 2 monitors?
if you are using HDMI to DVI, and a DP, can you use a different cable setup at all?
Another couple of things.
Are you using GeForce Expirience to get the drivers?
After the DDU, if you boot back into Windows(Not in safe mode, safe mode limits display output itself), do the 2 monitors work ok with the Native windows drivers(before you install NVIDIA's, the monitors should still work fine) ?
Are there any Windows updates waiting to be installed?
Is your Windows activated? Microsoft does restrict dual monitor use on inactivated Windows.
It will only work in mirrored mode if that is the case, or at lease that is how it used to be, maybe they've changed it.
Also, when did this start happening?
Is this a new build, has it worked before?
Did you change any of the cables or the monitors recently?
Has there been a windows update recently?
Open Reliability History and have a look if there is anything major there.
It is not as detailed as Event Viewer, but it gives a better perspective on the bigger picture.
I know there are a few questions here, but please try to answer all of them if you can.
Let me know if I need to clarify anything.