Hi,
I don't have the lightsnake cable so I can't help you in that respect, but I do have a B3 that works through my laptop (with crappy sound, but it works). Here is what I did (note that these steps worked for me but I didn't really know what I was doing most of the time, so I can't guarantee that they won't fry your laptop soundcard... maybe you'll want to wait for someone more knowledgeable to come by):
- Install Asio4All http://www.asio4all.com/
- Install the free version of Guitar Rig 4, launch it ensuring that no other applications with sound are open so that Asio can use the audio ports.
- Turn off microphone amplification if you have it on the Windows standard sound panel, set the input volume very low (but not zero).
- Connect the B3 to the laptop's microphone jack through an adapter (I use a jack to RCA and RCA to minijack adapters). If your laptop has a line-in jack I guess it would be better to use it, but mine, like most, only has a microphone jack.
- Turn the B3 on with low volume, because if your laptop is like mine, the B3's output will easily saturate the laptop's input and create distortion, so you won't be able to play at high volume.
- With this I'm able to play, I hope it works for you.
Why Asio4all and Guitar Rig? To tell the truth, I have no idea. I had installed them in my desktop computer to be able to add reverb to the theremin sound, but in that computer the theremin perfectly works without them (hooking it to the line-in instead of the mic-in). When I then tried the theremin with the laptop, though, it didn't work (due to the lack of line-in?). And then I installed that software and it magically worked. Perhaps Asio4all is able to use the mic-in as a line-in and the default Windows software doesn't do that... I don't know.