According to user reports Windows Defender seems to create thousands of files on the system disk of Windows 10. The problem started appearing after a faulty Windows Defender update is responsible for the mess.
Microsoft Defender is pre-installed on all versions of Windows 10 and is regularly updated through it Windows Update. After a recent Windows Defender update in the last week of April, many people noticed that Windows started creating thousands of files on the system disk, the place where the operating system is installed.
Affected users started reporting to Forums Microsoft and Reddit that the Windows Defender history folder (C: \ ProgramData \ Microsoft \ Windows Defender \ Scans \ History \ Store) was full of files. The files were tiny and harmless, but in some cases they used a huge amount of storage space.
The same bug was observed in Windows Server installations, with some reporting that it created 18 million files.
"We have three 2016 Servers affected. Our notifications for HDD space started last night. A server has 18 million files in the Store folder. Another has 13 million. It only takes hours to discover all the files so they can be deleted. And because of the size, these files take up 50-60 GB of disk space. "This is a big problem for Microsoft." he says a Reddit user.
How to check if Windows Defender is creating files
The easiest way to test your system is through File Explorer:
Open File Explorer and make sure “Hidden items” are allowed in the tab View.
In the address bar, type "C: \ ProgramData \ Microsoft \" without the quotation marks.
Click on "Windows Defender".
Click "Continue" if the folder requests administrator privileges.
In the Windows Defender folder, look at Scans \ History \ Scans.
If you're affected by the bug, you'll see hundreds or thousands of files each less than a megabyte in size. You can delete them with better safety.
Windows Defender in version 1.1.18100.6 fixes the problems
The good news is that the problem seems to have been resolved with the new version of Windows Defender 1.1.18100.6.
To install the update, look in Windows Update for a new update called "Security Intelligence Update for Microsoft Defender Antivirus".
You can see the version number of Windows Defender by opening the “About” page at application Windows Security.
