yes it does. does the hissing noise sound kind of like two surfaces rubbing against each other?

its hard to tell, the pitch changes, not only does it occur in games but in steam aswell, i hope you are familiar with it but just in case i shall explain. Whenever a friend comes online a box scrolls up on the bottom right part of the desktop/screen, when ever the box scrolls up, the pc makes the sound but it relates to the box scrolling up, when it appears the pitch gets higher and the same when it scrolls out, very strange, when the box is gone there will be no sound, its like one of those musical instruments that you blow into and you pull the actuator out the pitch gets higher relative to how far you have pulled it up the shaft , hope you know what i mean, i just heard a car outside and one of its belts was screaming, thats what it sounds like, a cars belt slipping but not as loud or high pitched

wow.. o_0 that is very strange... uhhhhhh.... lol try removing the sound card (if it is a seperate card) and unplugging the speakers if it is integrated.

will do lol

ok, took the sound card out - no change, still get the noise, the noise also occurs whilst scrolling the pages in steam, it seams any animation on steam makes the noise come. Steam and games are the apps that i hear it in.

I am running a memory test and the noise is more prominant, i havent completed the test but do you think it could be a ram fault?, i have tuned the system with ntune and it alters ram settings, could that be an issue? i shall report the findings of the RAM test when it finnishes.