USB connection on windows 10 phone not recognised

Hi,

I recently updated to windows 10 and when I connect my Z1 (5.0.2) windows doesn't recognise it...
I installed Sony PC companion but still nothing.
When I plug it in windows does detect that there's someting connected and when I check in devices and printers
it shows the model number C6903 under unspecified devices. I tried installing drivers in device manager but can't find any that works...
Has anyone else encountered this problem and was able to fix this?

Thanks!!