BleepingComputer.com: Can't hear some sounds - Windows XP

I don't use the sound a lot except to play You Tube videos for the kids. On one computer, some of their videos we can hear the backup audio but not the lyrics. I tried searching You Tube help and all over the Internet. Some sites say to check the audio settings. I went to control panel and sounds and looked at every option. I also clicked the sound control in the tray and went to advanced. All of the volume types are turned up. I don't know if it is related but it also sounds like the Bass is turned way up. I have an E-Machines boxed computer from the store. I don't have any special sound card or audio software. There is only a volume knob and balance on the speakers - nothing else. I'm assuming the kids managed to change a setting somewhere but I've looked everywhere and can't find anything. Please help!

Can I delete the post? I found the problem. Turns out that on volume control you can go into properties and check which volume controls you want to see. When I checked them all I found that the 3d sound was turned on. Finally have a very happy baby!