Is this any good for...

Recording guitars?

http://www.jgwindows.com/products/Cakewalk-UA22-Audio-Interface/JGUA22.html

Depends what you're doing/want mate.

If you're a beginner and/or just want to do some initial tests, I wouldn't bother with any USB stuff or big gear.

You can get a cheap cable straight into your line-in via any amp/distortion pedal for about £3-5.

Beginner haha.

I tried plugging the guitar through my DS1 into the line in and got nothing, hence..

Plus I'm hoping to use it to do all the music for the cartoon through it.

There should be no issues provided you used the right wire and everything plugged in okay, and you know your way around the windows sound/mixer console (if you are a beginner at that, it could be something as simple as forgetting to unmute / turn up one of the channels?). Once you can hear your guitar coming out the speakers you're good to record.

If there is still an issue I would look into having your sound card checked at a PC store - most will give you some quick advice free, as it could be a more serious issue that might affect other devices such as those via USB too.

Replacing the sound card alone would probably cost as much as a USB device so, personally that's my recommendation.

Hard to say more without being there / knowing the full setup.

I'll have a looksee and see if anything is muted.

EDIT : It gets a signal now, which is weird as it was exactly the same setup.

I'll have to look for stereo cables though, as it is only picking up mono sound.

A quick question.

Can you use the line in on the computer sound card for a keyboard?