No C Wire Nest Thermostat
What you need to do is to move the Blue wire at the furnace over to the "C" terminal at the furnace. Then at the new thermostat connect the Blue wire to the thermostat's "C" terminal. 

Note that at the furnace the White wire currently on the "C" terminal goes into a separate cable bundle that is paired with the Red wire in that same bundle. That cable most likely runs off to the air conditioning compressor unit.

It is not clear what the Yellow wire in the cable bundle from the thermostat connects to at the furnace end. There is a good chance that this is connected incorrectly or not at all. My understanding is that this Yellow wire should be connected into the "Y" terminal at the furnace where the miss-wired blue wire used to be.