Disk Cleanup is an essential Windows system tool which allows you to delete various unnecessary files created by the OS to save space on your disk drive. By default, it works in a simpler mode which allows you to delete only the files related to your current user account. You can switch it to the extended mode, which allows you to delete more unused files such as the ones used by Windows Updates, or service packs and so on. In Windows 10, the extended mode was updated to add one more feature. Now it provides a System compression option. Let's explore what it is about.