Problem resolved! I finally found the solution, I'll just copy/paste my post from another site :
Well! It finally works!
For the information of anyone who stumbles upon a similar problem. I ended up reinstalling the newest drivers of Realtek HD Audio via their website right here :
http://www.realtek.com.tw/downloads...=24&Level=4&Conn=3&DownTypeID=3&GetDown=false
Next, to my great displeasure, NOTHING was working. The sound was just completely cut off, my speakers weren't working anymore, Itunes, Flash and any application using sound would actually crash upon startup and I was getting pretty mad. The sound was just saying my audio devices were disabled, even though they clearly weren't and Windows Troubleshooting said it couldn't do anything.
After some more research, I found this wonderful article : http://www.pcgamer.com/2011/11/10/t...dows-7-audio-problem-solved/audio-problems-5/
And did exactly as he said, running command prompt in admin, type :
net localgroup Administrators /add networkservice
net localgroup Administrators /add localservice
before restarting your computer.
And voila! Now the sound works fine through my headphones AND through my TV!
The downside though, as explained in the article, is that this lowers the security of your computer, basically giving admin access to programs. To avoid this, he suggests simply resetting your Computer to factory settings, but since I actually had the problem with factory settings, I doubt that would help.
So anyway, issue resolved, thank you for your help.
EDIT : Oh, well good news! I was a bit worried about leaving these administrators rights like this so after re-starting my computer and making sure the sound still worked. I typed the reverse commands:
net localgroup Administrators /delete networkservice
net localgroup Administrators /delete localservice
Hence removing what I had just done. I restarted again and the sound still works fine. Try this if you are worried about the security problem.