Hey! This will be my first time posting a thread in this forum so please let me know if this thread is in the wrong category etc.
 
I finally got myself a midi controller/Audio interface. I'm using the Line6 Toneport KB37 and my input device and it works great. 
My output device is my 2.1 computer speaker system. I know allot of you probably have actual studio monitors but I've been doing some mixes with this setup and it sounds great to my ears so far. 
 
So here's my problem:
When my interface is plugged into usb, all audio is set correctly to monitor sound from Music Creator 5 although no other system audio is present. I have signal coming from programs such as Windows Media Player, Google Chrome etc. because I can see the levels jumping inside of my system audio mixer. When I unplug the Audio Interface, system audio then works again but audio from Music Creator is not present. 
 
So what I would like is to have system audio and audio from Music Creator to work seamlessly without having to unplug my interface.
 
Thanks so much and if you need more system info, just let me know please. 

"Help with using Line6 Toneport KB37 as input and computer speakers as output from computer"
 
Welcome to the forum.
That is not a good choice. Presumably, the Toneport has ASIO drivers for fast and efficient AD/DA audio conversion.
The stock sound card probably uses MME drivers which are not fast or efficient, so there will be a delay (latency) in the audio.
When using ASIO, you can only use 1 device at a time. If your sound card has WDM drivers, you may be able to use them and tweak the audio settings for acceptable delay. Still not a good compromise, in my opinion.
You don't necessarily need professional studio monitors. I run my audio through a stereo receiver connected to average speakers. It sounds okay to me, but I have bad ears. 
If you don't have active speakers, or a stereo receiver and passive speakers, you can probably pick some up cheap at a yard sale or pawn shop.
I recommend using the Toneport for all of your audio.

I agree with Greg 100%
 
why not just connect your 2.1 speakers to your toneport and leave them there for everything?  you can route all windows sounds and games or anything else through the toneport instead of thru the onboard soundcard where your speakers are currently connected.
 
just like Greg said:

I recommend using the Toneport for all of your audio.