Sorry if this is a noob post. I have a similar build. Pretty much exact:
-EVGA GT640 Graphics card
-16 GB of Ram
Now, I've been trying this for the past 2 days and its driving me nuts. Was working perfectly on HD4000, dual monitors and everything.
Inserted the card and nothing on either screens (kept one hooked up to the onboard graphics card and one to the GT640 via DVI.)
Tried different combos and everything. I know the Video card isn't bad because I tried in another computer and it worked great. Then tried messing with the BIOS settings under peripheral devices and selected IGFX only under INIT Display and Internal graphics enabled then it booted fine with the monitors hooked up to the internal graphics card. Not sure what the correct configuration is in the BIOS settings. Can someone point me in the right direction. Thanks in advance!