COM port not being assigned to my arduino ?

I have 8 USB ports on my computer, 4 of them have devices attached (external drive, mouse, keyboard, webcam) yet my device manager only shows 1 found under ports (COM & LPT). (This is my external drive plugged into COM1)

I have installed the drivers for my Arduino, yet when I plug my arduino in there is no indication that another COM port has been assigned to the Arduino.

When I run the Arduino software I see only COM1 under tool/serial (COM1 is my external drive)

Does anyone know how I can assign a COM port to my arduino ?

And on a related note: if I have 4 devices already plugged into my computer why do I only see one port assigned (COM1) ?

Thanks in advance.

Problem fixed.

I restarted my machine and installed a earlier version of the driver, now I can see COM3 has been assigned to my Arduino.