Audio big problems. No sound on windows 7. And that (S/PDIF) thing.

My regards to everyone.
I just joined here because i really need some experienced people's help. Not that i am somehow a noob in computer's industry,however,this problem was destroying me for the past few days.
This may sound like a few threads in one,and i am sorry for posting this as a new one,but i really need your help,because all the other threads i've read,on this and other forums,applied them,and no help whatsoever.

A few days ago,without doing something in particular,the sound just stopped working(does that sound familiar?). So as any other folk would do,i started every tiny little thing to fix that. So i cheched if the speakers,and then headphones,are correctly pluged in. They were. Then i tried disabling and enabling them from volume control options,then from control panel,u name it. Still nothing. So i uninstalled and re-installed my audio drivers. Again no use. I tried everything and literally got nowhere. So i thought it might be a glitch,and Re-Installed a fresh copy of windows. If it sounds familiar,from now on,this threat combines itself with others.
After reinstalling windows 7,my audio appeared as set to digital(s/pdif) and,ofcourse,no sound was available. The speakers and headphones appeared as unplugged. they were plugged in. So I went on the forums again,and saw that someone was informed to change something in bios. So i entered bios,and i saw everything was enabled,and set to HD Audio. When i looked at that,it said that i also have the AC97 option,so i enabled that(however,i always used optimised system defaults on bios,and HD Audio is the default,not the AC97.) Okay,so now i reboot and i can see that the computer is actually showing that i have speakers on right now,not that (s/pdif). So my heart is pumping,my eyes are shining,and i go straight on youtube,play a video aaaaaand....no sound. The sound bars however,are showing i have sound. And so i also try a troubleshoot. This troubleshoot goes along and at the end it says that i have no speakers plugged in. However,windows recognises them. And i know they areworking perfectly,i tried them on my phone,and on another computer. They are perfectly functioning. The audio,as you surely guessed,is an onboard card. I forgot to tell you that i also entered services.msc,and i have checked that windows audio is started.
Any help would be extremely appreciated. I simply have no ideea what to do anymore. Please,for the love of God,help me