Eventually bought myself a new keyboard, a Logitech G15. But when i installed it, i still had the problem with non working media buttons. So i went again searching for an soulution and found one!
I seems to be an startupentry which you manually have to change from manual to automatic.. If there are anyone having this problem, here is the solution:
- Go to controlpanel --> Performance and maintenance --> Administrative tools
- Choose services and scroll down to find "Human interface devices"
- Right click and choose properties --> and change startup type from manual to automatic --> Reboot and your media buttons should now be working again!
At least it did here, and i'm now happy with my new keyboard!