I just bought a new desktop with a GigaByte Z68AP-D3 Intel Z68 Chipset.
My monitor is connect via HDMI.
During its first run it installed Windows 7 Home Premium (trial version), skipping any BIOS or POST screens.
The OS is installed in a 60GB SSD. I decided to upgrade to Windows 7 Professional, so I inserted the disk from Windows and started the upgrade process using the GUI. I chose "Custom Installation" and choose to install in the same SSD of my current Windows. It gave a warning that I might lose my old saved windows items, but I proceeded.
After the upgrade was 100% complete, the computer restarted.
But it did not boot up to windows.
When I turn it on, my monitor says there is no signal -- No bios menu at all, and no Windows 7 Professional boot up either.
For some reason BIOS or POST screens are never displayed, and it seems the Windows 7 Professional installation didn't go smoothly so I can't even boot. The monitor just says there is no signal, but the mouse and keyboard do sometimes light up.
Try disconnecting each drive one at a time; one may still post. If you get one going, try connecting the other drive while windows is running so it is set up as a secondary drive. I clone my new drives; saves alot of time.