towers

I have very little usable c space on my laptop. how do I get rid of the crowding? I defrag and wipe w/ccleaner regularly including wise pc 1st aid. Computer is slow (crawling). Can this be fixed and how? Operating system:Windows 7 Home Premium (64 bit) Service Pack 1 System root: C:\Windows Available physical memory: 7928 MB CPU: AMD Phenom II X4 810 Processor Drive Info: C: 931.41 GB E: 931.51 GB I: 596.02 GB Internet Explorer: 10.0