vostizza

Hello everyone! this is an intermitent problem in my Sony Vaio model VGN-Z720D. I keep on getting a "No Audio Output Device is installed" when hovering my loudspeaker icon in Windows Vista Business. I have tried System >> Device Manager >> Sound >> Realtek High Definition Album >> Update Driver Software. The update process went through, but nothing happens. Still Vista does not seem to recognize my audio software. I have also tried to download newest Realtek drivers, install, unistall and pretty much everything. The strange part is that out of nothing my sound card can resume working to stop again hours later... I know that this is a wide problem and there are many forums talking about this but with no clear solution. If someone has any clues to solve this, please, help. Thanks a lot.