Audio problem

Hello everyone,
i formatted my comp three days ago. since then, every time i opened my computer, i had this problem:
-no audio at all: when i open a mp3 file with windows media player for example, this is the error:

"Windows Media Player cannot play the file because there is a problem with your sound device. There might not be a sound device installed on your computer, it might be in use by another program, or it might not be functioning properly."

and when i double click the Volume icon in the taskbar, i get this:
"There are no active mixer devices available. To install mixer devices, go to Control Panel, click Printers and Other Hardware, and then click Add Hardware."

So what i do is install the driver from gigabyte disk, or do the "add hardware" thing, and it's fixed: only until the next restart.

what might be the problem?

thanks in advance!

 

Check that Windows Audio Service is started.
Go to Control Panel>Administrative Tools>Services
Scroll down the list of services until you find the Windows Audio service.
Right click on it and choose Properties.
Make sure it is set to Automatic and Start is checked.

Also, go to the Recovery tab in that window and set the service to restart after 1st and 2nd failures.