I have installed 8.1 in a VHDX on a second SATA HDD drive in my laptop docking station. Even when not using Hyper-V (and having not started the virtual machine since rebooting into 8 which is on the laptop drive) I can see in Process Explorer that vmss.exe locks the VHDX. This prevents the drive being ejected as "This device is currently in use" message is received.

How can I avoid this? I can end vmss.exe but it is a bit of a bore to have to do it every time I want to detach the docking station.

Windows version is 8 pro x64.