I have an external USB 3.0 HDD as well as an internal SATA 3 HDD. I am unable to eject (ie "Safely Remove Hardware and Eject Media") either the drives because I get the error:
This device is currently in use. Close any programs or windows that might be using the devices, and then try again
I have checked the processes using the Resource Monitor and Process Explorer, and I am not seeing anything at all that is accessing the drive, especially the internal drive which is an empty, recently formatted backup drive (Process Explorer showed zero hits when I searched the drive letter).
Is there anything else I can do/check? It's not that I really need these features, but it's just bugging me that Windows won't let me eject the drives.
Most USB devices can be removed and unplugged at will. When unplugging storage devices, such as USB flash drives, you should be sure that the computer has finished saving any information to the device before removing it. If the device has an activity light, wait for a few seconds after the light has finished flashing before unplugging it.
If you see the Safely Remove Hardware icon in the notification area at the far right of the taskbar, you can use this to ensure that devices have finished all operations in progress and are ready to remove. Click the icon and you'll see a list of devices. Click the device you want to remove."
USB, it depends on hard drive enclosure sata controller, some simply don't want to work with safe remove feature.
you can try to disable write catching on that drive to make it safer for disconnects.
(i usually can hear when drive goes into stand by mode, (stops spinning)(windows feature) then simply flip power switch)
SATA internal - Usually if it show up under safely remove list it's bug, specially if your main (system drive) on that list as well
hot swapping sata you need special motherboard or controller card
it's pretty much impossible to simply safely remove sata HDD unplug from motherboard while system running on consumer products. (or if possible very unstable)