How do i set up guitar rig?

i have that guitar rig guitar recorder thing for my computer but i cant get it to work. i tried to set it up but when ever i try to record the guitar with it, it has this loud crackling sound and you can barely hear the guitar. im using it on a lap top with vista if that has any thing to do with it which would be stupid if that is the problem. anyway please help me because i dont want to waste all the money spent on it. by the way, i am very very computer illiterate so please put your instructions in laymans terms. also, can you plug the guitar into your amp and then into the guitar rig so that you can get the sound of your own amp or can you only plug the guitar directly into the guitar rig like i have been trying to do? thanks a lot and i will be reeeeeeaaaaaaaallllllyyyyy greateful to whoever can help me out.