It looks like a big watch battery. On your board it should be near "ASUS" between your PCI slot and your PCI-x16 slot.
Pulled it out, put it back, rebooted. Got nothing. Removed my GPU and used the i7 graphics and I got somewhere. Different issue now. Got the BIOS set up page, save and continue, windows screen momentarily, then bios screen momentarily, then windows failed to load screen.
Same thing happens over and over, won't even boot in safe mode.