can I record the sound that occured in computer?

not by mic,

I want to record the sound occured in computer.

Can I do it?

Oh i think u need a certain driver that creates an internal bussing soundcard, i forget what its called.

You can do it, If your audio interface that supports it.

You can always hardwire the output to the input, just make sure it’s not creating a loop.

have a look here:
I use this with success!