When a virtual machine is running, its window is the active window. If you plug a USB device into the host system, the device connects to the virtual machine instead of the host by default. If a USB device connected to the host system does not connect to a virtual machine at power on, you must manually connect the device to the virtual machine.

When you connect a USB device to a virtual machine, Workstation Pro retains the connection to the affected port on the host system. You can suspend or power off the virtual machine, or unplug the device. When you plug in the device again or resume the virtual machine, Workstation Pro reconnects the device. Workstation Pro retains the connection by writing an autoconnect entry to the virtual machine configuration (.vmx) file.

If Workstation Pro cannot reconnect to the device, for example, because you disconnected the device, the device is removed and Workstation Pro displays a message to indicate that it cannot connect to the device. You can connect to the device manually if it is still available. To manually connect a USB device to the virtual machine, select VM > Removable Devices > Device Name > Connect (Disconnect from host).

Follow the device manufacturer's procedures for unplugging the device from the host computer when you physically unplug the device, move the device from host system to a virtual machine, move the device between virtual machines, or move the device from a virtual machine to the host computer. Following these procedures is especially important for data storage devices, such as zip drives. If you move a data storage device too soon after saving a file and the operating system did not actually write the data to the disk, you can lose data.