Hi - I'm familiar with the usb reader and I have one and have tried my Canon memory card in it and the "PTP" does not show up on Explorer. I have another camera (Pentax) with a memory card and that card works great in the reader. The one that I'm trying to recover the file on is the one I'm having issues with. The light on the reader shows steady green and when I put the other camera's card in the reader it blinks green and it does show up as a SD, drive (e) in Explorer . So I know my reader is working properly, it's the memory card that's not. Should I format the "card" - my Canon has an option for a low-level format but it does indicate that all the data will be deleted?