Capture Source: Time Warner DVR
Capture Destination: IBM Thinkpad T41p
Capture Card: VStream USB
Capture Software: VirtualDubMOD

Situation:
Due to my situation, I am forced to capture using my IBM Thinkpad. Its a T41p. It has highspeed USB, for the video I am utilizing a VStream video capture box and that is working great. The problem however is sound. This laptop does not have an audio in port, only a microphone in. Now when I plug in there I am able to capture the sound but as you can well imagine there is a constant buzz through the entire capture.

Question:
How do I get rid of this buzz? I was looking at some USB Audio cards that have a line in port, but have not found anything that is priced reasonably and doesn't have a "LINEIN/MIC" port. I tested the audio capture on another laptop that did have a LINEIN port and the audio was captured clean so I know my cables are good, its just my port on my laptop.

So I am kind of at a loss here and looking for recommendations please.