Windows Defender never completes analysis.

Question

Hello.

I have been facing this issue on windows 11 for more than a year which obliges me each and every time to find alternatives antiviruses. Had to download Avast and Kaspersky for multiple times as my Windows Defender would never complete a full analysis.

It scans for less than a minute, stops at around 250 fields, than indicates that the scan is complete and no threat has been detected.

I have done my best to uninstall all residual datas from previous Antiviruses (without any result) using regedit and MyPc driver (Disk :C) folders. I also proceeded to RevoUninstaller and CCleaner (Both free versions)

The problem remains the same.

IF YOU THINK THAT THE ISSUE ORIGINATES FROM RESIDUAL FIELDS OF UNINSTALLED SOFTWARES :

I would like to emphasize that I cannot afford premium softwares to clean residues. If there is a way to completely delete all possible datas remaining from uninstalled antiviruses manually even if it takes time I would be happy to execute it.

IF YOU THINK THE ISSUE HAS OTHER SOURCES :

I would be thankful to receive solutions.

OTHER SOLUTIONS I HAVE TRIED : Offline complete analysis. Takes time but when I reboot my computer it doest show off in the history of scanning nor recorded as the last scan. Which I believe means the scan was not fully executed.

PLEASE NOTE : That this problem persists for more than a year, which means despite multiple windows updates, nothing changes

With thank's and hope for answers, Here is a picture (IN FRENCH) that summarizes the problem.

Answer 1

OK, it seems that malware has set a large number of exclusions.

• Run Windows Powershell as adminstrator.
• Select all the code below then press Ctrl + C to copy it
• Paste it into Powershell and press enter $Exts = (Get-MpPreference).ExclusionExtension Foreach ($Ext in $Exts){ Remove-MpPreference -ExclusionExtension $Ext -EA SilentlyContinue }; $Paths = (Get-MpPreference).ExclusionPath Foreach ($Path in $Paths){ Remove-MpPreference -ExclusionPath $Path -EA SilentlyContinue }; $Procs = (Get-MpPreference).ExclusionProcess Foreach ($Proc in $Procs){ Remove-MpPreference -ExclusionProcess $Proc -EA SilentlyContinue };

Then run the previous command to see if the exclusions have been removed:

Get-MpPreference | fl ExclusionExtension, ExclusionPath, ExclusionProcess, ThreatIDDefaultAction_Ids, ThreatIDDefaultAction_Actions        

If the exclusions are cleared, try running a scan.

Answer 2

I have installed CCleaner as I found no other solutions and thought residues might have caused issues. I needed to reinstall a third party Antivirus simply because windows defender does not complete analysis, and i can't leave my computer without protection.

CCleaner has been installed only after I uninstalled all other AV

Answer 3

Hello

Here is the screenshot :

Answer 4

Let's check if there are any exclusions set.

Type powershell into search then right click on Windows Powershell and run as administrator

Copy/paste in the following command > press enter:

Get-MpPreference | fl ExclusionExtension, ExclusionPath, ExclusionProcess, ThreatIDDefaultAction_Ids, ThreatIDDefaultAction_Actions        

Post a screenshot of the output.

Answer 5

Not a good idea to use any third party cleaner, cccleaner as it will have umintended consequences.

Simply run disk cleanup.

If a third party AV is installed in most cases it will disable Defender to prevent conflicts.

Iits not clear to me as to why you had the need to re-install kasperski or AVG,though you should only use the single third party AV (cccleaner would likley cause issues with both)