If a parallel/serial port is enabled in your Virtual Machine configuration, you can connect/disconnect port when running guest OS.
Note: If the guest OS is started with parallel/serial port disabled, you should shut down the OS first, then enable serial or parallel port in the Configuration Editor (select the Enabled checkbox in the Serial Port Options tab or Parallel Port Options tab) and restart the guest OS.
To connect or disconnect serial or parallel port, do the following:
Note: There is another way to connect/disconnect port. Right-click serial (
) or parallel (
) port icon on the status bar to display context menu and select the required command.