Windows Defender stopping me from ejecting harddrive

I have the same problem

Windows Defender\Platform\4.18.2009.7-0\MsMpEng.exe

October 2020

Doesn't Microsoft have a testing team??

Fix it!!

Unfortunately, MS is not doing anything to fix this, I have seen the same issue with Insider build 20236.1005.

The only way around for me now is by adding the external device or devices on the exclusion list for windows defender.

Assuming the device assigned letter(s) are the same each time you plug in the external device.

You would think that Windows system could release the device from defender when it needs to be ejected, but with recent changes it does not, it is really silly !😜

I also tried including the disk folder (E:) as you suggested, but still, Windows did not allow me to eject the hard disk. The only solution I have for this is to restart the laptop, but that is not a solution. Moreover, I am concern about what could happen with the data in the hard disk, as although I restart the computer I still have doubts if some data might be corrupted.

I also tried including the disk folder (E:) as you suggested, but still, Windows did not allow me to eject the hard disk. The only solution I have for this is to restart the laptop, but that is not a solution. Moreover, I am concern about what could happen with the data in the hard disk, as although I restart the computer I still have doubts if some data might be corrupted.

@Nekovolta, 

The exclusion list is not effective immediately, it requires a reboot to be activated.

It only works assuming that device letter(s) are the same when you insert the external drive(s).

Also it will only be effective if MsMpEng.exe is the cause of the problem.

You will need to check the Event Viewer, Windows Logs, System and see what the message for error 225 shows.

There could be other programs or processes that prevent the ejection, in that case the exclusion from defender will not help.

It works fine for me on 6 machines at Build 19042.662 and also Development Builds 20262.1010.

I've been using the exclusion for several months even before the defender platform was updated from 4.18.2009.7-0 to 4.18.2010.7-0.

The application \Device\HarddiskVolume3\ProgramData\Microsoft\Windows Defender\Platform\4.18.2010.7-0**MsMpEng.exe with process id 4380 stopped the removal or ejection**for the device  .....

I also tried including the disk folder (E:) as you suggested, but still, Windows did not allow me to eject the hard disk. The only solution I have for this is to restart the laptop, but that is not a solution. Moreover, I am concern about what could happen with the data in the hard disk, as although I restart the computer I still have doubts if some data might be corrupted.

@Nekovolta, 

The exclusion list is not effective immediately, it requires a reboot to be activated.

It only works assuming that device letter(s) are the same when you insert the external drive(s).

Also it will only be effective if MsMpEng.exe is the cause of the problem.

You will need to check the Event Viewer, Windows Logs, System and see what the message for error 225 shows.

There could be other programs or processes that prevent the ejection, in that case the exclusion from defender will not help.

It works fine for me on 6 machines at Build 19042.662 and also Development Builds 20262.1010.

I've been using the exclusion for several months even before the defender platform was updated from 4.18.2009.7-0 to 4.18.2010.7-0.

The application \Device\HarddiskVolume3\ProgramData\Microsoft\Windows Defender\Platform\4.18.2010.7-0**MsMpEng.exe with process id 4380 stopped the removal or ejection**for the device  .....

Does not work. Cannot even add the drive since it is not a folder or file or process or file type. Those are the only options. When you try to add the entire drive, it does nothing. Nothing gets selected even if I type it in manually and press enter or select.

Does not work. Cannot even add the drive since it is not a folder or file or process or file type. Those are the only options. When you try to add the entire drive, it does nothing. Nothing gets selected even if I type it in manually and press enter or select.

@BWX, 

Looks like you did not understand how to add it:

It is the root folder of the drive.

E:\ 

F:\   

or other drives...

In order to add to the exclusion list, the drive must be inserted, you add a Folder then you select the drive you want to exclude and click on Select Folder and it will add it to the list.

Then you just reboot and you are done.

See screen shots below for adding Folder E:\   

(  F:\ was already added in this sample)

I will try again but it would not add anything last time no matter what I tried.