According to user reports, Windows Defender appears to be creating thousands of files on the Windows 10 system disk. The problem started after a faulty Windows Defender update that is responsible for the mess.
Microsoft Defender is pre-installed on all versions of Windows 10 and is regularly updated through Windows Update. After a recent update to Windows Defender last week in April, many people noticed that Windows started creating thousands of files on the system disk, that is, 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 filling files. The files were tiny and harmless, but in some cases 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 user at Reddit.
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 the “Hidden items” are allowed on the View tab.
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 are affected by the bug, you will see hundreds or thousands of files smaller than one megabyte each. You can delete them safely.
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 entitled “Security Intelligence Update for Microsoft Defender Antivirus”.
You can see the Windows Defender version number by opening the "Information" page in Windows Security.
