This has been a problem with a ZL and I realize this is a Z foum but since there is fa rmore people here...
Installing the Sony companion app installed
USB Mass Storage Device
SONY Mass Storage USE Device
I tried the procudure for bootloade runloc from the Sony Mobile site and it does installs the drivers but they all end flagged by Windows 7 and 8 as won't start.
Been doing this for 3 days and no luck.
Any help would be highly appreciated.