Acer aspire e 15 laptop no sound after upgrade window 10

Hello,
Please how should i do?My laptop no sound
After reinstall window 7.i have tried troubleshooting way but still have problem.
I forgot keyboard shortcut way.last two month
I can solved this problem with keyboard shortcut way when i upgrade window 10.but
I don't remember which key i press for turn on the sound back.Please gud me how can i do?
I am very sorry my english language.Thank..