Issue With Laptop

[The Claw]

I have a Korg M3 hooked up to my laptop via cable connecting the audio out of the M3 to the Mic In jack of my laptop. Everything works fine except when I play something directly on the M3 I can not hear it through my laptop as it is extremely quiet. My laptop speakers, the M3's volume and the recording volume of the laptop are all at max so I know it's not a silly mistake I have made with regards to volume levels. Can anyone help me make the sound louder please?