I tried this morning to install Windows 8 but I don't have enough space in my C drive.

I have an Asus All in One Desktop ET2410 IUTS BO34C.
It is divided into C drive and D drive.
My C drive has 13.6 available out of 79.9 GB
My D drive has 242 GB available out of 365 GB

I tried installing Windows 8 but it needs 20 GB of space in my C Drive. All currently installed programs only make up 1.97 GB.

Can I install Windows 8 on this computer without reformatting my computer and causing lots of problems for myself?