Even if I was going to upgrade I would not recommend it right away. Windows 10 is still too new with possibly too many potential bugs and driver issues. I would wait until January at least. You’ve got a full year to take advantage of the Free Windows 10 upgrade. That being said:
A female client just recently upgraded her laptop to Windows 10 and lost her sound in the process. I immediately noticed that the sound icon in the system area (down by the clock) was muted. So I enabled it and then tested a media file to see if that cleared it up. It did not. All the drivers seemed to be installed and set up properly.
Looking online, there seemed to be a lot of people having the same issue. One suggestion was to update the drivers by going to the device manager, right clicking on the sound card and choosing update driver software. Tried it, drivers updated but still didn’t work.
The suggestion that worked for me was to go to Control panel > Administrative tools > Services, look for the Windows Audio service and stop it – you can just right click on it and click “Stop”.
I’m not sure if it was necessary but I also did the same thing for Windows Audio Endpoint Builder. Then you just right click on each again and start them up again. Sure enough it worked.
Except for this one lady, I don’t personally know anyone else right now running Windows 10. I know that will change with time. When my desktop conks out on me and I go to buy a new one, more than likely it will be Windows 10 and I’ll just have to learn to live with it. But until then…