I've fixed my problem.
I knew I needed to select speakers instead of S/PDIF but there was no option for speakers. So after a long process of trying every driver for my motherboard I could find Including the latest ones from the realtek website I decided to try the
High definition Audio codecs
which can be found here Realtek
after installing this I was able to select speaker and my sound works fine.
I hope this works for you. Now I've got some boot problems to solve...