So my friend has the audio adapter that has a 1/8 input that goes into your computer and in the back of the adapter you plug in your guitar cable or 1/4 jack thing. Well i couldnt find one at Radioshack so i had to get this long ass chord that has a 1/8 jack at the end and a 1/4 jack at the end the only thing is that its a stereo to stereo so i need another adapter thats stereo to mono to go from that to my guitar cable and my amp is a Marshall MG15CD (yea i know) and it has an emulated headphones jack to put the guitar cable from the computer or there is an emulated line out to put the cable in. So the problem is that when i plug it in either one and go into my recording software (mixcraft ) and arm it and play nothing happens?

If anyone as any idea wut im talking about please help me.
Guitars/ Basses:
PRS SE singlecut w/Tremolo
Epiphone Sg
Epiphone Thunderbird

Waiting in the wings:
Squier Strat mod
(soon to start)

Line 6 Spider JAM
Peavey Max 115 bass amp
you should run an audio interface, not go though a stock sound card (as these were not made to record and will give you latency)

you do have to set your inputs in the recording program so it knows where the audio is feeding from in order for it to record. Some software wont work without a good interface, Sonar Producer being one of them.

Also see this:

I would say mic your amp but if you had to you can run from the headphone/line out on your amp to the interface but it usually doesnt sound as good as micing the cab...