After I have captured the audio from my cassette tape player, there are 2 files produced. One titled Audio.mp3 and the second titled Audio_1.mp3. They seem to contain the same material as checked with Windows Media Player but one is slightly larger in size.
What's up?

The usual reason you'd end up with 2 files like that is if you captured one with the file name Audio and then captured another file with the same name.

If on the first page you hit Advanced a box pops up that lets you set the capture location and file name.The default file name is Audio.
Did you start and stop the capture?If you did it would create multiple files,all with the same file name except for the number(_1,_2,etc)

I found out what is happening. I tried an experiment.
I captured about 30 seconds of audio and then quit the program altogether without exporting or burning. I found that a file named Audio had already been saved.
When I capture and then export (same session) to my hard drive, a second file is saved with a name of my choice or else Audio_1.
Confusing, but I now know what to expect.

Thanks for your reply.

Glad you got it figured out.