No Stereo Mix/Wave Out recording option on NewGateway laptop with Vista pre-installed

I have exhausted every attempt to get some kind of resolution to this problem. I make music for soundtracks and commercials independently, utilizing virtual pianos and sound generating programs. While the purchase of this Gateway MT6821 notebook was specifically for these purposes, I am unable to record any sound that the computer generates (sound generating program and recording program running at the same time). The reason for this is simple: no "stereo mix" or "wave out" option appears in the "recording" tab in "sounds". I checked the "show disabled devices" and "show disconnected devices" and there is still nothing in the window besides the "mic" and "cd" options. To make things worse, I called Gateway, Microsoft, and Gateway again. No help or apparent knowledge was available, nor were they enlightened. I went back to the retailer where I bought it, and found that not one Gateway laptop had this feature (all the Toshibas did). Gateway said that there is no update for my soundcard driver. I'm really stuck here. I can't take my computer back because I waited too long to open it, assuming the sound properties worked as they did on my other Gateway and HP both running XP. Temporarily, I rigged my headphone and mic jack, but the quality needed is not present. Any help would be greatly appreciated, thanks.