Windows 7: Error using Stereo Mix

I really need to use Stereo Mix on my sound, but it won't show up on the Recording Device panel. I have checked both "Show Disabled Devices" and "Show Disconnected Devices" and it's just not there. Under the Device Manager it says that I have an "ATI HDMI audio" (I don't know what that means ) and the manufacturer is Realtek. I am not very good with the details of sound devices so any input would be very much appreciated.

Hello, neighbor (I'm just up the road in Inverness).

The ATI HDMI Audio is the audio from the Video card for HDMI only. Your regular PC audio is the RealTek.

I see you have a Dell Alienware. In most cases we have found on the Dell forums that you must use the Dell sound drivers. There have been cases on some older Dell systems where the System Mixer (Stereo Mix) was not available but I haven't heard about this on models for the last year or two.

Check the Device Manager again to see if it lists both the RealTek and the ATI HDMI Audio in the audio devices section. If both are showing, Uninstall the RealTek in the device manager (DO NOT check the box to uninstall the drivers) then restart the PC and whwn Windows starts it will detect and reinstall the sound. If there was a corruption in Windows for the sound this will fix that. Then check to see if you can get the Stereo Mix.

Your best place for the Alienware help is the special Alienware support forum on the Dell community forum. Lots of users there that are familiar with Alienware's. Dell's forum is down right now for some maintenance but it should be up later today.
http://en.community.dell.com/

Update, the Dell community user forums are now available .

Here is the link to the Alienware support section
Alienware Club - Dell Community

Okay, so in the device manager is says under Sound, Video, and Game Controllers it has "ATI HDMI Audio" AND "High Definition Audio Device" is that what you mean?

Yes. The "High Definition Audio Device" is your PC sound device. Normally that will state what it is such as RealTek, IDT, etc and that may be the problem.

Without the actual Alienware model number I can't verify what the sound device is.

Do you recommend that I uninstall it, and if so how would I go about doing it? And I checked, it is manufactured by Microsoft if that helps at all.

You can uninstall the device by going to the Device Manager, RIGHT click on the entry for the device and then LEFT click "uninstall". Then restart the PC and when Windows starts it will detect and try to install it. Cancel that function and then install the correct Dell supplied driver.

Again, as I've noted the best place for support is the Dell Alienware forum section.