Ok. I'll try to restart the computer---thought I did that while I was in Ethiopia and it didn't make a difference.
How do I make sure that memory card is in the 'unlocked' position? I didn't fuss with it when this problem first occurred.
Give me a minute to get back to you as I'm going to try and sign off and back onto my computer.
Tried this but hasn't worked. I may go into a camera shop. I expected my USB memory card reader to work but it doesn't. It's got to be something wrong with the memory card...
I'm going to try calling a camera shop and I'll let you know what happens.