I want to record from my keyboard into my PC (Adobe Soundbooth software) for video, but my cable has a USB jack and my sound card only has a line in port. I've tried changing the audio hardware preferences and default, but still couldn't get anything, even from the mic I was testing with. The PC says my midi device is working properly, and the mic worked when plugged into the sound card. Soundbooth Help says I should be able to record from MIDI, so my problem is can I get a MIDI cable with a line in jack instead of a USB jack? Or is it something else entirely, like maybe I changed my audio hardware preferences wrong....

MIDI is not audio.
To record your keyboard to PC use the keyboard`s Line Out or Headphone Out jack and connect it to the soundcard Line In or Mic In.
If it`s really MIDI you want to record then you need to connect to the soundcard`s MIDI IN via its MIDI port, unless you have USB to MIDI software in which case you should have a cable with USB one end and a MIDI the other that goes to your instrument... looks like the old DIN plugs.
Afraid there`s not much else I can say about it without more info...
What Operating System?
What souncard (and what connections does it have)
What make / model keyboard - and what ins and outs does it have.

Just a thought - MIDI is usually presented to a soundcard via the Joystick port using a dedicated MIDI in/out cable

Are you aware that MIDI is just an instruction set which tells a sound module what notes to play and how to play them? I don`t know what level you`re at, so sorry if this sounds too simplistic.

Hope this helps

How are you getting on? Did you sort your sound problem?

Thanks for answering! I'm an audio neophyte, so no you're not being too simplistic - lol. I have the M-audio midisport UNO cable that goes from the MIDI ports to a USb jack. I only have the software that comes with that. Will that not enable me to record sound into my PC? Obviously not, right? So I just need to use an audio cable to run from the headphone port to the line in port? Will that enable me to record?
Windows XP
Diamond Xtreme sound card with speaker jacks, mic, line in and SPDIF (no MIDI)
Yamaha PSR-420/320 keyboard (old) with MIDI in and out, sustain (whatever that is), and headphones ports

Being a good little audiotooler, I've read the tutorial on using the headphones port when copying tapes to PC...will I have to be careful of the volume if I connect the headphones port to the line in port from my keyboard to PC? All I know about MIDI is that it stands for Musical Instrument Digital Interface, and that my keyboard has two funny-looking spots on the back that are labeled such -

Thanks for the help, I've tried everything I can think of, and my hair is lying about in tufts on the floor...

First I think you need to Google up some MIDI info so you understand just what it does.
However, if all you want to do is record the SOUNDS that you make with your keyboard then yes, just connect it`s Line Out, if it has one, or the headphone out to the Line In of your soundcard.

If this is your card
http://www.pcper.com/article.php?aid=200&type=expert&pid=1
then yes, it does have a LINE IN socket. This will be stereo and will happily take a cable from your keyboad headphone out, but please keep the levels down at the keyboard.
For recording you can used the bundled AUDACITY software or you could try KRISTAL. Both are Freeware tho KRISTAL lends itself better to multitrack recording but doesn`t handle plug ins.

Now, MIDI.
Your card does not have a joystick port so you don`t have the "usual" MIDI interface, which I suppose is why you bought the MIDISport.
You`ll connect the MIDISport cable from your keyboard MIDI OUT to the USB on your PC..... and from here is where I can`t help you in any precise way because ..
There may be a setting on your keyboard to initialise MIDI and configure it..... the manual will tell you. And there will be a way to tell Windows and your software to expect MIDI via USB... again, I don`t know how that will be done. I have only used MIDI through the joystick port and then rerouted out to an external sound module, which brings me to my last point..
IF you get your MIDI set up to record INTO your PC, all you will be "recording" (bad term that) will be instructions to the soundcard. Each instruction will say to it something like;
"Play C3 now, play it this loud and this hard for this length of time, and play it on a piano (or whatever instrument you have chosen)..... and stop playing it... NOW! "
There will also be instructions for effects, modulation, aftertouch and other stuff.
Let`s say you record a 64-bar sequence... you will find that the resulting file is only a few KiloBytes... that`s because it`s not audio, it`s just a list of instructions and can even be read in Notepad.
Now you want to play it back.... you tell your software to Open the file and Play it, but Windows and your software need to know what to do with it...... play it with the soundcard`s onboard instrument sounds? Nowadays they`re not bad at all but probably won`t be as good as your keyboard.
Or play the sounds using your keyboard? To do this you now need to hook up your keyboard`s MIDI IN to the USB (but you probably already did that).
Press Play and hope that the information now reaches your instrument.
I`d recommend Cakewalk Express for MIDI use as it`s a nice compact program which has been around a long time and will be more than adequate for all but the most demanding use. And the Help file is pretty good. I *think* it`s free nowadays but I could be wrong.
Hope this has been helpful.
Good luck with your music.

Well, no wonder I wasn't getting what I wanted! Sounds like the headphones-to-line in is going to be the answer, and yes, that looks like my sound card. About the software - I'm guessing the two you mentioned are particularly for music, and unfortunately I'm a beginner there also (more visual than auditory, I guess). What are plug ins? Is the software pretty easy to use? I had some music software once that may as well have been written in Greek. Anyway, you can't help me there, I know...lol
Thank you, modo1, you've straightened things out for me a lot... (Do I really need to Google midi now? :D)
Thanks for the good luck wishes, too. I'm going to need them!

Audacity sotware comes with your soundcard. I have it but don`t like it much. I use Kristal for multitrack and Soundforge 6 for individual track editing.

A plug in is simply an extra piece of software to provide tools effects and facilities to help you work with your sound files.
You`ll get stuff like reverb, echo / delay, noise reduction, pitch bend/pitch shift etc.. you get the picture.
The beauty of plugins is that they can be recognised by many other programs which are more than happy to work with them.
I currently have a set of plugins which work with Audacity, Soundforge and Cakewalk Pro Audio even though they weren`t written by these software manufacturers.
I guess you won`t need to Google MIDI now unless you decide to go down that route.
Good luck