Windows 10 Antivirus Bug Quietly Fills Your Hard Drive with Gigabytes of Files May 6, 2021 12:58 GMT Windows Defender on Windows 10 A recent Microsoft Defender, also still referred to as Windows Defender, has caused some devices to be filled with unnecessary files with a size between 1 and 2 Kilobytes. While Microsoft has remained completely tight-lipped on a whole thing, a report from German site DeskModder points to several discussions on the company’s support forums where users are complaining that their Windows 10 devices ended up with thousands of mysterious files stored at the following location: C:\ProgramData\Microsoft\Windows Defender\Scans\History\Store By the looks of things, all files are placed there by the antivirus, and one users claims they ended up with close to one million files at the aforementioned location.