What is the "o" drive?

When loading a file from a thumb drive, I get a notice that the file exists on the “O” drive. should I use the “O” drive file or the file on my thumb drive?

You’ll have to be a little more specific.. not sure what you’re getting at here…

My error. I read the C drive as O. Another question, when does the thumb drive data get transferred to the C drive?

as soon as you load it it will be copied into CNC 12