After a malware attack, Windows Defender Settings interface may show the message Some settings are managed by your organization. Also, the real-time protection and cloud-based protection options may remain disabled.
Here is how the Windows Defender Settings page might look like. The controls for real-time protection, cloud-based protection and Automatic sample submission options may be disabled and locked down or grayed out.
If you’ve installed a 3rd party anti-virus, Windows Defender gets disabled automatically. It’s normal. This post tells you how to activate Windows Defender real-time protection and other settings, by removing the entire Windows Defender registry-based policies, which were previously added by malware, or added when you used a 3rd party tweaker, or privacy protection tool.
Caused by a third-party privacy protection tool?
If you had used (or using) anti-spy tools such as O&O ShutUp10, make sure you reset all “Windows Defender and Microsoft SpyNet” settings in O&O ShutUp10. Here is how it should look after resetting them.
Caused by malware?
First, make sure you eliminate malware completely with help from expert or friend — given the complexity of the malware infestation, professional help may be suggested. You may also try Windows Defender Offline, additionally.
Malware removal procedure is complex, and is beyond the scope of this article. After removing the malware completely, remove the registry-based policy settings for Windows Defender which were added by malware.
Remove Windows Defender Policies using the Registry Editor
Automate the following registry modifications using defender-policies-remove.reg (zipped). Unzip and run the enclosed REG file.
After running it, you may want to open the Registry Editor to make sure the “Windows Defender” Policies key doesn’t exist. Once done, restart Windows for the changes to take effect.
1. Start the Registry Editor (regedit.exe) and go to the following branch:
2. Export the branch to a REG file. Then, right-click the “Windows Defender” key and choose Delete.
3. Similarly, backup and delete the following branch:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Advanced Threat Protection
4. Exit the Registry Editor.
5. Restart Windows.
Note that this completely clears the policy settings for Windows Defender. By default, in a clean installation of Windows, no policies are set. Windows Defender Settings page will now look like this.
Important: After removing all the policies, you may want to enable PUA or adware protection in Windows Defender. If you had already enabled the setting before, you’d need to re-do the procedure now.
Remove Windows Defender Policies using Group Policy Editor
If you’re using Windows 10 Professional or higher editions, the relevant Windows Defender Group Policies are available in the following branch of the Group Policy Editor (gpedit.msc)
Computer Configuration > Administrative Templates > Windows Components > Windows Defender
There are atleast 95 policy settings, with the items in every sub-branch put together. You need to set each setting to “Not configured”.
Allow antimalware service to startup with normal priority Turn off Windows Defender Configure local administrator merge behavior for lists Turn off routine remediation Define addresses to bypass proxy server Define proxy auto-config (.pac) for connecting to the network Define proxy server for connecting to the network Randomize scheduled task times Allow antimalware service to remain running always
Also, check the following sub-branches in the above location, and set each Policy setting to “Not configured”.
Windows Defender\Client Interface
Display additional text to clients when they need to perform an action Suppress all notifications Suppresses reboot notifications Enable headless UI mode
Turn off Auto Exclusions Extension Exclusions Path Exclusions Process Exclusions
Configure the 'Block at First Sight' feature Join Microsoft MAPS Configure local setting override for reporting to Microsoft MAPS Send file samples when further analysis is required
Windows Defender\Network Inspection System
Turn on definition retirement Specify additional definition sets for network traffic inspection Turn on protocol recognition
Configure local setting override for the removal of items from Quarantine folder Configure removal of items from Quarantine folder
Windows Defender\Real-time Protection
Turn off real-time protection Turn on behavior monitoring Scan all downloaded files and attachments Monitor file and program activity on your computer Turn on raw volume write notifications Turn on process scanning whenever real-time protection is enabled Define the maximum size of downloaded files and attachments to be scanned Configure local setting override for turn on behavior monitoring Configure local setting override for scanning all downloaded files and attachments Configure local setting override for monitoring file and program activity on your computer Configure local setting override to turn on real-time protection Configure local setting override for monitoring for incoming and outgoing file activity Configure monitoring for incoming and outgoing file and program activity
Configure local setting override for the time of day to run a scheduled full scan to complete remediation Specify the day of the week to run a scheduled full scan to complete remediation Specify the time of day to run a scheduled full scan to complete remediation
Configure time out for detections requiring additional action Configure time out for detections in critically failed state Configure Watson events Configure time out for detections in non-critical failed state Configure time out for detections in recently remediated state Configure Windows software trace preprocessor components Configure WPP tracing level
Check for the latest virus and spyware definitions before running a scheduled scan Allow users to pause scan Specify the maximum depth to scan archive files Specify the maximum size of archive files to be scanned Specify the maximum percentage of CPU utilization during a scan Scan archive files Turn on catch-up full scan Turn on catch-up quick scan Turn on e-mail scanning Turn on heuristics Scan packed executables Scan removable drives Turn on reparse point scanning Create a system restore point Run full scan on mapped network drives Scan network files Configure local setting override for maximum percentage of CPU utilization Configure local setting override for the scan type to use for a scheduled scan Configure local setting override for schedule scan day Configure local setting override for scheduled quick scan time Configure local setting override for scheduled scan time Define the number of days after which a catch-up scan is forced Turn on removal of items from scan history folder Specify the interval to run quick scans per day Start the scheduled scan only when computer is on but not in use Specify the scan type to use for a scheduled scan Specify the day of the week to run a scheduled scan Specify the time for a daily quick scan Specify the time of day to run a scheduled scan
Windows Defender\Signature Updates
Define the number of days before spyware definitions are considered out of date Define the number of days before virus definitions are considered out of date Define file shares for downloading definition updates Turn on scan after signature update Allow definition updates when running on battery power Initiate definition update on startup Define the order of sources for downloading definition updates Allow definition updates from Microsoft Update Allow real-time definition updates based on reports to Microsoft MAPS Specify the day of the week to check for definition updates Specify the time to check for definition updates Allow notifications to disable definitions based reports to Microsoft MAPS Define the number of days after which a catch-up definition update is required Specify the interval to check for definition updates Check for the latest virus and spyware definitions on startup
Specify threats upon which default action should not be taken when detected Specify threat alert levels at which default action should not be taken when detected
If some of them already read as “Not configured”, “Enable” the setting, click Apply and set it back to “Note configured”. This is to clear the registry values correctly.
About the author
Ramesh Srinivasan founded Winhelponline.com back in 2005. He is passionate about Microsoft technologies and has a vast experience in the ITeS industry — delivering support for Microsoft's consumer products. He has been a Microsoft MVP [2003 to 2012] who contributes to various Windows support forums.