Windows users can use a free utility called WinDirStat;
Deleting dozens of old accounts individually can be a chore, however. Account Killer is a free service that can help you quit hundreds of popular services with a few clicks. Simply type in the name of a website – or browse the complete list provided – and you’ll see a colour-coded button. For “white-listed” services, Account Killer provides a link directly to the relevant deletion page.
Remove optional Windows features
To review and remove installed language packs, open the Start menu and type “lpksetup”.
Windows 10 also comes with numerous preinstalled Store apps. Clearing these out involves typing in a few commands but it’s easy to do: see here for instructions. For the nuclear option, search the Start menu for “Reset this PC”: this will remove all installed apps and revert your PC to a pristine state, while keeping your personal files safe.