ASUS G73JH Audio and system lag

Hi there! I have been having some really frustrating issues with my PC, and I was hoping that someone could shed some light on the matter.

For about 7-8 months I've been having some pretty frustrating problems with my Asus G73JH; Audio and system lag is the best way i can describe it. Randomly, but often, my PC will get short lag spikes where the computer and image freezes for 3-5 seconds. Sometimes more, sometimes less. What usually accompanies this is a lag in the audio, where the audio gets stuck in a loop for about the same duration. However, the audio and image lags can happen independently of each other.

Theese freezes can happen when just moving my cursor around the desktop, while im browsing files, or when im playing games etc. Some programs however are worse than others. For instance, SMITE and Archeage are really sensitive to this problem, and it happens frequently while im browsing through files aswell. When im playing Sui Generis, listening to music or watching stuff on Netflix on the other hand, these problems VERY rarely occur. Needless to say though, this problem is super annoying.

I've tried updating graphics drivers and audio drivers, which didn't help. I've tried updating my BIOS which didn't help either, and I've several times done a "Reset to factory settings" when booting up the PC. This didn't help either. Searched around for this on the internet, but haven't found any solutions to the problems that I am having, so decided to post this here, and will do elsewhere too.

If you are still with me and can offer any help, it would be greatly appreciated. If there is any more information that I can provide to help you help me, then I will of course do so if you state it.

Cheers for taking the time to read, and possibly replying!