Hello StefaNafetS and welcome to Seven Forums.
Was your computer having any audio problems before you installed the updated Realtek driver
? If it wasn't having any problems I'd go back to the previous driver. You can use a previously made Restore Point. System Restore
Or, you can roll back the driver.
1. Open Device Manager.
2. Locate the device that you want to roll back the driver for (probably under sound, video and game controllers.)
3. Right click on the device's name or icon > click on Properties.
4. In the Properties window click the Driver tab.
5. Click the Roll Back Driver button (If it is disabled, Windows 7 does not have a previous driver to roll back to.)
6. Click the Yes button and the previously installed driver should now be restored.