Thank you for your answers to my questions, I will try them all out and will let you know where I was going wrong.
I have now printed out Bebop's instructions on how to zip and unzip files and when I have read and absorbed the info hopefully, I'll not get wrong again.
Bebop - sorry about not giving notification of my instruments - I have the Technics PR900 piano (my first love) and the KN6500 (my new love). I have to say, the KN6500 is consuming all my time at the moment because I recently had the SX-3 hard drive fitted and am slowly loading all my disks (approx.150) onto it. However, it is taking longer than I thought because I keep getting 'itchy fingers' and just have to sit and play the keyboard. I'm sure you all know what I mean.
Thanks again all.