SpaceSniffer is a freeware tool that allows you to have an idea who the files are structured on your disk. It is portable and doesn’t need any installation. After launching it you need to start a scan. Bigger are the elements on the view, bigger are folders and files on your disk. SpaceSniffer gives you more detail on one portions if you click over it.
This free software allows you to understand where are located bigger files and make some free space by deleting old backups. Another great feature is that you are able to exclude file types.