Clearing CMOS on a DQ45CB motherboard

I have a new DQ45CB, which produced no video using the default on-board graphics system. I put in a pci-e graphics board, and the screen appeared as it should have.

I went into the CMOS BIOS, and foolishly changed the default video setting from AUTO to Inboard, thinking that might force the native display to work. It did not, and of course I could not get back to the BIOS to change to AUTO.

I removed the battery, and waited one hour, as an Intel support document recommends. This has had no effect.

Any recourse?

Thanks in advance,

Michael