Originally published at: Fix: No Sound After Installing Windows 10
Many users of Windows 7/8 and 8.1 have lost sound after upgrading to Windows 10. This issue arises because the currently installed audio driver is either not compatible or has been corrupted during the upgrade process, leaving the user without sound/audio. There are a few methods that usually fix the issue, which we’ll discuss in…
There are symptoms you need to look at; and the error messages which indicates the direction to take.
Thank you. You are so nice.
Sometimes, I just don’t know if the problems are caused by device drivers. So I use a driver updating software to verify. I am wondering how do you find the reasons when you face a problem? Please advise. Thanks. 
I do not recommended driver updating softwares, because they contain malwares. The same thing can be downloaded from the manufacturer’s site as stated.
Finally, I finished reading. Thank you for your tips, but it could be better if the word looks more bigger … anyway. I can’t hear anything after I upgraded to Windows 10. There was a big red X on the speaker icon. As nomal, I used Driver Talent to scan my machine and I could see the sound card driver was outdated from the scanning result. Then I made just one click, Driver Talent downloaded the best-match one for me. I’d like to say, it is better to check out the reasons before propose a solution, right?
Follow steps here: Windows Update: FAQ - Microsoft Support then re-apply the fix. Let me know the results then after reboot.
The problem with this “fix” is the next time you reboot it happens again. I hate this stuff. Every time Windows has a new version they don’t bother to make sure it works with audio, which is a huge problem for anyone who can hear.