I had a lot of problems initially trying to sort out the computer compatability with my Zoom 4.
Zoom 4 card needs upgrading to a higher volume card,as soon as you get it . I use mine in conjunction with a card reader "Sandisk" this was the turning point for me I can delete recordings easily ,down load them as MP3s to post off etc.
For a non computer person this sorted out all my problems.
Al