I downloaded the Xperia_Z1_SO-01F_driver from Sony and also got the Sony PC Companion neither of them helped me detect the com port on my Win 7 PC but I am able to view the files in my Z1. Ironically I tried to detect the device on an other Win 7 without installing Xperia_Z1_SO-01F_driver or Sony PC Companion but it still shows the folders on my phone but not the COM port. Appreciate any input.
I'm not sure what you are trying to do. Your phone connects through USB, and that driver you wrote about is an USB driver. You don't actually need to install any drivers on Windows 7 and above, the OS will recognize.