Computer still slow after using CCleaner

I've installed CCleaner and still my pc is very slow. Can anyone help?

There could be tons of other reasons why your computer is slow. CCleaner is not a guarantee to speed up your system if there are OTHER causes that are slowing it down. Could be a fragmented hard drive, virus, defective software, hardware damage or simply a dusty CPU.

Look into this article:

http://www.qozan.com/10-things-that-slow-down-your-computer/

Also it would help to give more info such as operating system used, what security software you have installed and any other problems you have noticed.