Windows 7 Disable USB COM port?

[Degibbo]

G'day all,
If I disable or enable a com port (USB device) via the driver under device manager,
the acton performs perfectly provided the port is not open.

If the port is already open, I get a message that hardware has changed and that a
restart is required. Why the difference, and how can I disable a port that is open?

Cheers & thanks
DG

 

[Neemobeer]

If the port is open the disable operation is stored as a pending change since it can't be disabled while open. That is why it states a reboot is required.

 

[Degibbo]

Thanks Neemobeer,
That makes complete sense, but now it looks like I will have to interrupt the USB cable wires with a relay to cobble an open port!
I haven't been able to find a way to do this in software.

Cheers,
DG