Then, in another case, there is a considerable possibility that the hard drive of your desktop is bulking up with redundant data, duplicate files etc. causing fragmentation and slow speed. Fragmented data sucks up more space just like the haphazardly piled up stuff in your room.
So, what needs to be done is to defragment it timely and remove the duplicate files. But the task of searching duplicate files is quite gruelling as well as stodgy. What is required here is a utility to intelligently clean up the duplicate files on a click.