I've been able to install the latest sound drivers after rolling it back to a couple of weeks ago. No change at all and now for some reason other areas of the Pc have started acting up as well. It will just suddenly restart and then says a conduction error with the IDE control and then start up and restart again as normal. Programs suddenly crash now every few minutes and processes just abruptly say they have a problem and close. I have checked the hard disk and its fine from what I can see, I think that there must just be component failure somewhere on the motherboard and the hissing was just the beginning.
I think I will get another motherboard if this keeps up as its just impossible to use the pc. I might get the same one or a different one but similar.