Hi lcdsantos,
If you can hear sound that means the drivers are correctly installed and working, so thats not the problem...I guess you may have forgot to set the correct 'default' device for sound to use the correct output for other applications
Control Panel\ Sound\ Playback-Tab
Right-Click the Audio Device and click 'Set As Default'
Sometimes Windows will automatically set the device as 'Digital Output' and require you to set 'Speakers' as the default device, It might also help to use the 'test' option located there to determine the correct output device and then set that one as 'default'
Steven