distorted and crashied audio during playing dvd

Hi,
I have a problem with in my pc. After a month holiday, i came back,
switched on my pc, it automaticaly updated itself, and I did not find
a difference untill i played dvd movie. The audio / sound is
distorted, and watching movies looks like hard workout. I do not have
this problem during playing .avi, mpg, or any other movie and sound
files from my hd and dvd's. It comes when dvd format is played. No
matter which software is used.
I do not know what to do, windows dvd troubleshooter does not have
answer, all of my software is licensed, and updates automatically. I
tried ASR but it doesn't wanna back up files from 2 months ago. I
checked device manager, control panel, all of the sounds settings and
found nothing. I know that reason could be somewhere in the dvd
drivers. But how to find it.
Please, if any one knows what to do with that, I would appreciate any
help.

Thank you,

thomas