I spent a lot of time trying to figure this one out. I have 4 x 4 GB SanDisk Cruzer Edge sticks and although my Windows 8 machine would pick them up, I couldn't copy/paste to them or format them. Long story short, for some reason having Samsung Kies installed on my machine was preventing me from using my sticks. When I uninstalled Kies, they worked immediately. Not an ideal solution but, I use the sticks way more than I use Kies and I can download it again in a minute.