Windows Defender keeps blocking a third-party program that I know isn't a threat. All my attempts to disable Windows Defender have failed.
I've tried to:
How do I turn it off permanently?
In Windows 10 Professional, you can disable Windows Defender via the Local Group Policy Editor (gpedit.msc) by enabling the Turn off Windows Defender policy in the following location:
Computer Configuration/Administrative Templates/Windows Components/Windows Defender
In Windows 10 Home, it can also be done via an elevated command prompt:
reg add "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection" /v DisableRealtimeMonitoring /t REG_DWORD /d 1
To roll back:
reg delete "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection"
This isn't a solution to turn off Windows Defender entirely, but I think it's a better solution to what you're actually looking for. You can turn off Defender's Realtime Protection, without turning off Defender altogether. If you want to be able to use Defender to do on-demand scans (not realtime scanning), then this solution is useful.
Open up the registry editor with Start -> regedit.
Navigate to Computer > HKEY_LOCAL_MACHINE > SOFTWARE > Policies > Microsoft > Windows Defender
Navigate to Real-Time Protection. If that key doesn't exist, create it under the Windows Defender folder. (note the space between "Time" and "Protection")
Inside Real-Time Protection, add a new DWORD value.
Name it DisableRealtimeMonitoring and give it a value of 1.
You may need to reboot. This will now allow Windows Defender to run on-demand, but if you look in the Defender settings, real-time protection will be turned off and grayed out.
Type in Defender into the search bar, and click on the Defender program in the list. When Windows Defender opens, click Settings and turn off real time protection. I just noticed that it will reenable it automatically after some time, geez.
I suppose you will could install some third-party antivirus software that does not flag hack tools and such as a threat. There is a third-party application called NoDefender to disable it permanently, but I have not tried it or can vouch for it or what it actually does to accomplish this. I found this note on another website, but I am not sure if it is true or not. Better make a restore point anyway.
NOTE: The NoDefender utility doesn’t include an option to enable Windows Defender again. So we suggest you create a manual system restore point before disabling Defender if you want to easily enable Windows Defender again in the future.
Another method is to rename the Defender program folder. This must be done from a Linux Live DVD or USB: C:\Program Files\Windows Defender.
Another method is to disable the Defender Service from starting in the Windows registry as it cannot be done from Services directly as options are grayed out.
Open regedit and go to
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinDefend
Open the subkey corresponding to the service you wish to change (WinDefend), and modify the value of 'Start' to equal either "2" (for automatic), "3" (for manual), or "4" (for disabled).
(Registry edits have the advantage for Windows Home or lower versions, as they do not have Group Policy Editor to do it as suggested by Nate's answer.)
Save this text as a .reg file and execute:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender]
"DisableAntiSpyware"=dword:00000000
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection]
"DisableRealtimeMonitoring"=dword:00000001
This disables only realtime which helps to speed up the computer.
Set the first value to 00000001 to fully disable it.
gpedit.msc and Enter
gpedit.msc and Enter
I could post an answer on how to turn it off, but based on the background you shared, I decided to give a different answer.
As you shared in comments, you already have an exception added into Windows Defender which allows your software to work as expected. In your question you did not indicate any performance or compatibility or other issues which in some corner cases can be reason for disabling the protection tool completely.
To address only your specific blocking issues, you have found the proper solution. This is the purpose of exception lists in threat-prevention software and you used it in the right way. You gave no reason why it is necessary to disable the entire protection instead of adding just one exception.
Any weakening of security of your computer is generally only worse. Do not switch off Windows Defender if the problem has a valid working solution (for example, using the exception list).
Alternatively you can replace Windows Defender with other protective software, e.g. with an antivirus program or security suite. (They will turn off Windows Defender, too.) But it may happen that they will cause a conflict with your application, too, and you will end up adding a new item into the exception lists as you did it for Windows Defender.
UPDATE regarding current voting +15/-12:
Based on the comments, it is possible that guidelines for answering are not in common knowledge of many users of this site. Answers pointing to problem found in the question, replying with "don't do that" and proposing another solution are perfectly legitimate. I understand some users are landing at this question when emotionally charged against the Defender, but based on the above, please think twice before voting down. Happy knowledge sharing!
Go to Settings, Security, Virus & threat protection, Manage settings, Tamper protection. Set to Off. Then add this:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection]
"DisableRealtimeMonitoring"=dword:00000001
Windows will re-enable defender after reboot, the best way is to create a powershell script and set it on a scheduler to run on windows start up.
Create a file called defender.ps1 store it under C:\ and enter the following line
PowerShell Set-MpPreference -DisableRealtimeMonitoring 1
Configure windows scheduler to execute the script on windows start up with the following arguments -ExecutionPolicy Bypass -command "C:\defender.ps1"
The only thing that worked for me was to delete MSMPEng.exe. I followed this tutorial.
I held down Shift, then restarted Windows.
Click "Advanced Options":
Click "Command Prompt":
Enter:
RD "C:\ProgramData\Microsoft\Windows Defender\" /S /Q
RD "C:\Program Files\Windows Defender\" /S /Q
