I had many an issue with this board going from a 8X AMD rig to a 12X rig.

** If you want to access BIOS; be sure you are plugged into the onboard graphics.
** Double check riser USB cables; aftermarket longer ones wouldn't work.
** If you can't boot up with 1 GPU plugged into the PCIE_16x slot to install windows; install using on-board graphics, then switch to GPU after you are done changing settings in BIOS.

This is just to name a few..

I still have the issue of no workign start menu or search block even after installing all the latest OS and drivers.