Few things you can change that can free up space on the C: drive.
1: Right click recycle bin>properties and resize how much it can store. Most likely has around 7 GB set for it.
2: Shrink how much the system restore has reserved. Typically I set mine to 5GB which is more than enough but windows likes to give itself about 12%. Also cleanup your old system restore points if you have loads, I generally keep about the last 3.
3: Clean junk from the C: drive that windows has left over especially after a win upgrade. C:\>properties>disk cleanup>clean up system files>tag em all and go.
4: Move the pagefile to spare partition on a second drive that isnt used much. Having it on the SSD uses up alot of space and doesnt make alot of difference to performance seemingly.
I know some of these are just "reserved" for space and not necessarily actually used but i find it helps down the road with saving space.