Either mic the amp or use a line out from your amp to an interface that's hooked up to your computer. Or go directly into your computer if you have an instrument port, though it'll almost certainly sound like shit.
Forget anything built into you computer, or any sound card you have for games.

You need an interface, or an proper audio PCI sound card.

Assuming its a PC, best bet is go in the USB port with something like this:


(see also Line 6 stuff, etc etc, and check out



You can connect the line of your amplifier to the interface box, or plug in a microphone (Shure SM57 is the industry standard, (beware copies)) pointed directly at your speaker.

You'll need some software (basic stuff willl come with interface) - check out Reaper.
Quote by ZachJohsnon1984
As stated in the title how do i do that. i have a kustom quad jr half stack..HELP

Guitar to Amp To PC

Guitar to USB Audio Interface To PC with Amp Sim

As much as you might want to use your amp, unless you have an awesome mic, and an awesome soundroom,AND an audio interface, this is your best bet imho. Use your amp for jamming.
If you're amp has a line-out, FX send, or a Preamp-out, then you actually can go from Guitar to Amp to PC. You'll just have to use some sort of cab emulation (impulses) to make it sound nice as pure preamp signal is nasty and fizzy.

I suggest getting an interface before you do anything though.
Easiest way to do this. If you own Rockband, Guitar Hero, or any other game that gave you a USB mic, take that mic and plug it in your computer. Then use a stand to hold the mic to your amp. If you mess around with the position of the mic relevant to the amp then you will produce different sounds. It's a recording technique I picked up while reading a book on home recording.

Quick Setup:
1.) Plug USB Mic into comp
2.) Plug in guitar to amp
3.) position Mic in front of amp
4.) Hit audio record and play

Thats what I do! For quality check, just listen to my MP3s good luck!
Stuff :]