I think he wants to use his PC as a logic analyzer, and input the signals through the parallel port. There have been a few hobby projects like that, but they have dried up and blown away, probably because the timing quality is so poor.
USB? Not sure what he means, unless he is referring to commercial products. There are many commercial analyzers that communicate with the PC through the parallel or USB port, but they use external hardware to acquire the signals. Windows simply displays the data.
You could search back issues of Circuit Cellar magazine for hobby projects similar to the commercial products. Try December 1997 or October 2004 issues.