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.