Device manager, Sound, video and game controllers, what audio codecs, devices show? The top of the list is usually the driver being used. If Updates has installed the wrong one then right click the top audio driver/codec/ device (whatever it shows) and select 'update driver software'. Select 'Browse my computer for driver software'. Select 'Let me pick from a list of device drivers on my computer'. The new window should show a list of drivers. The icon on the left that is a blue colour is the one selected and not working. Click a driver below the top one and select 'next'. You might get a warning that your non working sound won't work. Select ok anyway. Test it for audio. You can always revert to another latent driver exactly the same way. You might have more choices than me but I have three or four.
What is ransomware and how do I protect my PC from Petya?