Uno writing / reading data to / from Computer HD

Hello all,

I guess I confused you all. I have a Uno connected to my laptop with the standard USB cable. What I want to do is as part of the Sketch I would like to read from and write to a file on the laptop HD.

I do not want to add a HD to the UNO or add an SD card.

Is that clearer?

Thanks in advance for your help!