What OS were you using on it before? What does it show in Device manager for that sound device? Does it show unknown device in there? What is the manufacturer & model of the computer you are using 8.1 on?
before : windows 7 64 bit
no it doesn`t show that it`s unknow it`s a gaming pc that i have bought each piece separately + i think it`s a driver problem how to find my best driver ?
You need to post the Motherboard model, or if the computer was bought as an OEM. The manufacturer & model #. If it is the later. Just go to the manufacturer support website and pull up the specs. If it is a Realtek HD Sound chipset. You can go to Realtek to download the driver.
What you can do if you can not figure out the motherboard if this system was built for you, or the OEM support site is not clear. You can download Speccy from majorgeeks.com. It should be able to tell you what the sound chipset is.
I have found that some Windows 7 systems did not work properly with Windows 8.x.x. So they were reverted back to Windows 7.
Personally I look at it. That if the system worked fine with Windows 7 SP1. There is no need to go with Windows 8.x.x. Now of course there is a way to pull info from systems with Linux. But that would require downloading a Live DVD and knowing how to read the output of lspci in the Terminal window.
I just ran lspci on my computer that I am on. Which is running Xubuntu 14.04. It came up with the Sound chipset as an AMD, due to it is built into the AMD CPU/GPU on my laptop. Speccy should work out for you to find out the sound chipset info. If as I stated before, that you cannot find it on the motherboard or computer support site.
It does not appear that Gigabyte has a Windows 8.x.x capable Audio driver for your motherboard. You may be SOL and stuck using Windows 7 with that Motherboard. You may want to try and contact Gigabyte and see if they have info on a compatible Windows 8.x.x audio driver.
In my line of work. We call that "Planned Obsolescence".