My original goal was to be able to record a video file from what plays on the screen - not just the video, but the audio as well. CamStudio is freeware that does this, so I downloaded it to my desktop computer (Windows XP). It worked great except for the lousy codecs I have installed on that particular desktop. So I downloaded CamStudio to my laptop where all the good codecs are. I have a Dell E1505 Inspiron running Windows XP that was bought in June 2006. It came with a SigmaTel HD Sound Card. Video was excellent but there was absolutely no sound at all. So, I started fiddling around with the sound properties in th control panel. I compared them to the computer on which Camstudio was recording sound and found less options under recording control. This problem has been encountered by other Dell laptop owners and I resolved it. Hopefully this helps someone else.
Go into Start > All Programs > Accessories > Entertainment > Volume Control (or just double-click on the speaker icon in the lower right corner of screen, if you see it). Go to Options > Properties. Here you should see the name of your sound card (SigmaTel). Where it says "Adjust volume for...", click on "Recording". The list under "Show the following volume controls" is where the first difference was noted. My desktop C-Media Wave Device had six things, including stereo mix and wave. The SigmaTel options only included line in and microphone, which is NOT what I was looking for. I was mad because I paid a lot of money for the laptop and it was newer and assumed to be more capable of tasks than the desktop. If you see stereo mix in this list, this is what you need to have checked off in that list. If you don't see it, you can't record sound through the sound card. You'll need a mic or either a double-ended line-out to mic in cable. And that would be a pain. OK let's assume you see stereo mix in the list. Put a check in the box and click OK. Generally, it's best to check off everything you see. It doesn't activate any settings, it just changes what you can control. Now your recording controls come up. Put a check mark in the Select box under Stereo Mix and make sure no other check marks are on. That works - as long as you have stereo mix as an option.
To get it as an option, I found a driver to install. I didn't uninstall the original driver first (I probably should have, but I didn't), I just downloaded the exe file and let it do its thing. Go to LG Electronics Service Online :: Home, click on product support, go to device driver. In product, select notebook (I think it's only notebooks by Dell or IBM that have the issue) and type SigmaTel in the search box. You're looking for SigmaTel sound driver version 126.96.36.19966 or newer. For me, it was the second in a list of three for Windows XP OS. Download it, click on the exe file and let it go. Reboot, and then try it again. Double-click on the speaker icon for the volume controls, etc, as outlined above. Stereo Mix is now there, and audio can be recorded.
Believe it or not - Now I have audio with either no video or still video. But it may be something silly because I was fooling around with some of the settings late last night and I don't know what I may have done while I was frustrated, before I solved the audio issue. If anyone has had this issue with the xvid or divx codec, please help because I have little experience with those settings and bitrate calculator and target quantizer and what ?!@! I usually just keep what I had last that worked by accident. It gave me an encoder error and asked if it could use the default encoder (Microsoft 1, whatever the heck that is). I said yes just to see if it would give me a file with audio and video. Then it gave me the first frame still with the audio sounding great. Anybody have suggestions about xvid or divx settings?