If there is nothing on D, you should be able to go into Windows Disk Management, highlight D, right click, and delete it. And then extend C into that space.
But---there are advantages to having a C and a D. And it is very odd that your C drive of 110 GB is full after 1 day of use---unless you have installed some large games? I have no idea what Tom Tom is.
On a standard installation, I would expect C to be under 50 GB on average. Mine is only 28 GB.