Is there a way to hotswap an external HDD when using Backup and Restore in Windows 10

I've seen this message once in a while and surprisingly enough, it often had nothing to do with the last software that used that drive.

It was Firefox.

I speculate (and this is pure speculation) that Firefox looks at all the drives available when it starts up, and somehow creates an unwanted attachment to them which prevents ejecting the drive until Firefox is closed.

In those cases where it wasn't Firefox, looking down the list of active programs would usually suggest a program that still had the device open, and closing that program would solve the issue.

It's a pity that there is no way to easily scan the list of active file descriptors.  That would reveal the perpetrator of this situation.

I shutdown all active programs, including Firefox and tried ejecting the external HDD and it still comes up with the same message, that it is still in use.  Any other ideas?

Windows Explorer will also lock up a device.

Hmmm.

I've had this on a number of portable drives just recently inserted eg CD/DVD drives  and flash drives.  You've inserted, copied a couple of files over in one direction or the other and then want to detach and the message pops up.  Go away for 30 seconds (or slightly longer) and all is OK.

I'd try again after 5 minutes and see if it is OK.

In my case I suspect either a virus scan is occurring or there are file cleanup/closure operations (Windows Explorer?) that haven't been completed.

... to expand on what dbrunton has said above, check to see if write caching is enabled on the drive.  If so, disable it.

You can force the removal by removing the drive letter using a diskpart script, for example and the eject it.

try stopping it with safely remove : https://safelyremove.com/index.htm

I see this all the time with a particular customer.

Their QuickBooks manager will capture the external drive IF the system reboots (security updates, etc) with the external drive connected to the system.

Per kenfcamp's comment:

Check the BIOS settings to see how USB / removable storage devices are treated ... if such settings are available.

If the BIOS is set to treat removable storage as fixed then it's plausible that Windows could treat a removable USB drive as a fixed drive, and that would certainly make it impossible to eject.

When I checked the process ID that was hanging onto the drive, 4, it was the system.  My solution was to go into Disk Management and select the drive in question and take it offline.  At that point I was able to eject the Ext HDD properly.  The next time I connect that Ext. HDD, I have to bring it back online and it works fine.  Thank you noxcho!

You are welcome John!

Someone should write this thread up as an article (and collect 3000 points), since EE is seeing similar problems about once a month.  (No, it's not going to be me.)