Sorry for the delay, Just got back from holiday.
I tried your suggestion, but it didn’t work. I think the problem is driver related, because ‘adb devices’ returns an empty list of attached devices.
My phone appears in windows device manager ‘Other’ as ‘S57’, but shows a ‘no driver installed’ error. I have tried manually updating the driver from AppData>Local>Android>sdk>extras>google>usb_driver, but it does not recognize any driver files.