No volume from Helix 2 tablet after upgrade to Windows 10

[Rotherhaven]

Just upgraded my Helix 2 (20CH) to Windows 10 (from factory installed 8.1). All fine apart from the fact that the volume is incredibly quiet when the tablet is used by itself, even if all mixer controls turned up to 100%. Almost inaudible in fact and most definitely not usable.

Seems like I'm not the only one, an internet search reveals that this is probabaly a fault with the Windows 10 driver for the Realtek HD audio device. Apparently it is missing the Dolby software needed to make the speakers work properly.

As machine is in warranty I raised a Service Request and Lenovo insisted that the only way round the problem was to reinstall 8.1 !

Then they said "we cannot offer support for software issues" which seems pretty incredible for a machine that should be fully supported under Windows 10.

Can anyone help here - is there a workaround, or some way I can persuade lenovo to fix its driver ?!

Regards and thanks in advance