Cannot safely remove my external HDD

[Nelumbo]

This is doing my head in, so hoping someone can help, or at least reassure.

I am using Windows 10 and have a WD passport external hard disk drive that I use to back up my photos and videos, I have plugged it in and safely removed before with no issues

However this time round when trying to eject it gives an error message that

' this device is currently in use. Close any programs or Windows that might be using the device and then try again'

There is nothing running at all.

I've gone round and round on Google and found people having the same problem but there are so many different answers I don't know which is correct!

What I did discover though was if I go into disk drives and properties it is set to the default quick removal option saying you can disconnect the device without using the safely remove option
This says that write caching is disabled, but I have no idea what this means so my worry head says i still dont want to just unplug it.
I have a lot of stuff on there that I am terrifed of losing

Can anybody help?

Shut the machine down. Unplug the hard drive. Restart the machine.

Thanks @phoneLock I was contemplating doing that but couldn't find a clear answer as to whether that was safe either!

Quick removal operation is enabled because write caching is disabled (if the drive was unplugged with cache enabled everything stored in cache would be lost). Disabling write cache makes writing to the disk a lot slower but safer. I still wouldn't just unplug it though .
As phonelock says, switching off the machine should be OK.

Maybe a virus check was running against the files on the external drive?

Once the laptop is off it’s safe to unplug the external drive.

You occasionally get that error when a program has terminated in an uncontrolled way and not tidied up.

You should be able to restart the computer then eject it.