What do I need?

I just bought this mic -

http://www.amazon.com/CISNO-Condenser-Microphone-Recording-BM800/dp/B00M6NEBD6/ref=sr_1_2?s=musical-instruments&ie=UTF8&qid=1420783769&sr=1-2&keywords=BM+800

and found out that I would need a phantom power supply.  However someone was talking about a preamp and an interface.  I don't need professional grade gear here, I just want to be able to use my mic without it sounding extremely muffled.

Can't you just buy an external USB soundcard and connect the microphone to that via XLR? Or am I missing something?

I have no clue that is why I am asking...

It says on the page this microphone Doesn't require phantom power so you should be able to just plug it straight into your microphone port on your PC.

 

See that is the problem, then why does it sound so muffed.