No sound in media players

Ok here`s the thing. When i tried to update my sound card (realtek hd audio) everything past great but now i can here windows sounds, youtube, but there is nothing from media players. WMP is saying that I have to install driver for my sound card. I tried everything, new drivers, system restore....
please help...

More info?

Have you tried any other media players?
For example, Media Player Classic K-Lite Mega Codec Pack asks you what speaker set-up you have during the install.

Have you checked the Realtek control panel to see if the correct output jacks are set.

I have three OS on my PC.
My Realtek card worked perfectly in XP and Windows 7, but it didn't make any sounds in Ubuntu.
It turned out that Ubuntu had chosen the wrong device type during installation (Stereo instead of HD Audio).

Sometime after that incident:
I thought that my sound card was playing up, when I played an anime episode which had 5.1 sound.
The sound didn't seem to be working properly (the Windows sounds were normal).
It turned out that most of the soundtrack was directed to a different output jack (I only have stereo speakers).
It was the only series that had this soundtrack set-up.