For those who don’t know, Disk Cleanup frees-up space on your laptop or desktop machine by spring-cleaning files that you’re not using on a regular basis. While running the application certainly clears some room …users often keep things they haven’t finished with in their Downloads folder.
Microsoft never assumed it was safe to ditch everything from your Downloads folder – the option wasn’t ticked by default. Instead, it seems users ticked the option (as well as number of others) without knowing what the ramifications would be, probably pleased at the amount of disk space shown that they’d gain.
This option has clearly caused a headache for Windows 10 users across the world.
source: express.co.uk