SOLVED Windows Defender Anti-Virus Options disappears [CU/ 1703]

[Airider]

After installing CU/ 1703, Windows Defender Anti-Virus Options disappears and sometime randomly returns, else with System Restore (to a point well AFTER installing CU/ 1703). I want Limited Periodic Scanning to always be on or available (so I can manually check for and download new definitions)
.
How can I bypass the Windows Defender Settings window and directly force or access "Windows Defender Anti-Virus Options "?

 

[Regedit32]

Are you running any other antivirus / security software on the computer?

If you are that may be disabling Defender.

 

[Airider]

Windows Defender will run properly with both Kaspersky AND RansomFree (I uninstalled and problem persisted ... when it occurred). No WITH t runs fine with both Kaspersky AND RansomFree for hours or days after 1703/CU was installed, then periodically turns off Periodic Scan and itself!

The (limited) Periodic Scan is in 1703 located in the "Windows Defender Security Center" which many times over the past few days becomes no longer reachable, so the "Windows Defender Anti-Virus options" is then NOT there!! Clicking on "Windows Defender Security Center" will in these cases lead to and show an incomplete panel for LESS than 1 second, and then revert to the "Windows Defender"panel (all of the above through Settings). Yes it "should" always be on. Windows tricked me into downloading an UNIDENTIFIED 1703/ CU update instead of allowing me months for MS to sort out all the bugs ....

As admin.I need a cmd, etc., route directly when this happens again so that i don't have to use System Restore to turn Periodic Scan BACK ON!

 

[Regedit32]

Under normal circumstance, when you install a third party antivirus application the following occurs:

1. Windows Defender Real-time protection is deactivated
2. When you open Windows Defender Security Center, and open Virus & threat protection an additional link is now provided where you can if you choose to turn on periodic scanning.

If I understand you correctly, this feature seems to disappear on you, or not function as expected.

If there is no Third party antivirus application installed or enabled, the periodic scanning feature will disappear.


If you do have a Third party antivirus installed and running, but the feature option is not present it may help to add a new Registry value to Windows Defender policies:

• Open an elevated Command prompt
• Type or copy & paste the following:

REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender" /v DisableAntiSpyware /t REG_DWORD /v 0 /f

Press Enter key

Data value of 0 = Windows Defender enabled
Data value of 1 = Windows Defender disabled

That may force Windows Defender to remain active for you. Worth a try anyway.​

 

[Airider]

Thanks, that is exactly the kind of Command Prompt I was seeking (if it happens again, so far not yet again) .... so long as the above regedit does NOT enable Defender "Real-time protection"!

To be redundantly clear, I want Defender to be running in the (limited) Periodic Scanning mode, always .... but NOT "Real-time protection", since I value Kaspersky a LOT (and now also RansomFree as an adjunct which uses behavior clues rather than definitions and seems to have many competent supporters)

Further, with Defender Periodic Scanning enabled, as it now is, I can use that window to search for and download a new Defender definition whenever I wish (else it comes through Windows Update which I cannot use since I am on metered Internet access and limited to 1GB/day and need to SELECT and standalone download Updates)

I will try this (if needed) and post if it worked ....


re:

If I understand you correctly, this feature seems to disappear on you, or not function as expected.

this seems to be a common and well-reported issue now with CU/1703 so maybe MS will fix it

 

[Regedit32]

Well if you want to ensure Real-time protection is off you can also add the following to your Registry:

• Open an elevated command prompt
• Type or copy & paste the following:

REG ADD "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection" /v DisableRealtimeMonitoring /t REG_DWORD /v 1 /f

Press Enter key

To re-enable Real-time protection

REG DELETE "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection" /v DisableRealtimeMonitoring /f

​

Alternatively you can also use an elevated PowerShell console:

• Open an elevated Windows PowerShell
• Type or copy and paste the following to turn Real-time Protection off

Set-MpPreference -DisableRealtimeMonitoring 1

Press Enter key

To turn Real-time Protection back on:

Set-MpPreference -DisableRealtimeMonitoring 0

​

 

[Airider]

That is great. a very useful tool to use when/if needed (so far, so good)

Thanks MUCH!

For the record, my clever Danish ex-wife was a (code-writing) 40-man Group Leader at MS Redmond (I helped her through all the joys of "C++ Forever") in Testing, and with all those millions of lines of code it is a wonder that they ever get anything to work at all, really

 

[Regedit32]

Cortana probably just collected that post and sent it to your ex-wife

I'm glad it appears to be working for you now.

See how it goes over the next day or so, and if things remain satisfactory, mark your thread as solved.

 

[Airider]

OK. it is still working with above solution (System Restore, which INCLUDES keeping Kaspersky & RansomFree), will now consider it solved until further notice