http://support.mozilla.com/en-US/kb/No%20sound%20in%20Firefox http://support.mozilla.com/en-US/kb/No%20sound%20in%20Firefox#w_other-solutions thank you

You can click the Volume icon on the Windows Taskbar near the clock and click the Mixer link at the bottom to open the mixer.<br /> You can adjust the volume level for each application in that window, so make sure that Firefox is not muted or set at a low level.<br /> Current Firefox versions use the plugin-container process to run plugins, so you need to check the volume setting for the plugin-container process.<br /> You will only see the Firefox program or the Plugin Container in the Mixer if you are on a website that plays sound.<br />