No Sound Coming from Laptop

Hello,
I'm using Windows 7 Home Premium and somehow the sound just stopped working. Both the inbuilt speakers and my headphones have no sound at all. Earlier when I've tried plugging in my headphones, there was some sort of static or white noise coming out of it and a few days ago, the same thing happened to my speakers. I've tried scanning for any errors with Microsoft Diagnostic and they've came up with nothing. My drivers are all installed and it's not a problem with the volume. Is the problem cause by the Hard or software? And is it possible to fix without sending it for repair?