What's the problem with my Memory Cards?

Factual Questions
1

I am attempting to copy jpg photos from my computer onto a 1GB SD Memory Card. My computer has an internal card reader.
I selected all jpg files that were on my hard drive, did CTRL-C to copy, and then pasted them onto the drive for the memory card.
It simmered along just fine for a couple of minutes, copied several hundred files, when I got this message popup:

Error Copying File or Folder
Cannot copy DSC_0415.JPG: The directory or file cannot be created.

When I now look at the properties of the drive for the memory card, only about a third of the card has been filled. If I attempt to copy any additional file at this point, I get a message like the one seen above.

This same phenomenon is occurring on two different memory cards, of different brands.

What is my problem here?

2

You can only have a fixed number of files/folders in the root directory. Make a folder (you’ll have to delete a jpeg or two first), and put all the pictures in the folder.

3

Success!

Thanks.