Hi Dandraghas,
I am Dave, I will help you with this.
Windows has limited partitioning capability, it can only extend a partiton into space that is directly to the right of the partition and between the C drive partiton and that space, you have the Recovery partiton.
You will need to use a 3rd party partitioning utility like the free version of AOMEI Partiton Assistant to extend your C drive partiton