Personally I would recommend downloading and installing EaseUs Partition Master, it is easy to use and will accomplish what you want with ease. I should point out that it is possible to achieve with the use of 'Create and Format Disk Partitions' which you will find if you search for it on your laptop. You would need to 'shrink' 'C' and then create a partition in the unallocated space. If you opt for EaseUshttp://download.cnet.com/EaseUS-Partition-Master-Home-Edition/3000-2248_4-10863346.html
Click on your 'C' Drive and choose 'Resize/move'
Using your mouse, move the bar at the end of your drive from right to left until 'C' is the size you want. This will leave unallocated space for your new partition, and when you choose 'Apply' the operation will take place when you reboot Windows