Problem with images transferred from Mac to PC

Hi, I'm new here, so hope I've posted this in the right place...

I used a pen-drive to transfer images from my iMac OS9 to my PC laptop...I expected the Mac to reject the pen-drive because it's so old (the Mac not the pen-drive), but it seemed OK so I saved JPEG copies of the images, and got them on to the pen-drive, but when I tried to open them in Photoshop Elements 2 (bundled) on the PC (running Windows XP) it said Photoshop couldn't open them because they were the wrong type of document.

I copied them to a folder but they only appeared as an icon.

I've got a bundled version of Corel Photo Album 6 on the PC, and they opened as an image in that, so I clicked Save As, saved them again as JPEG, and then they opened OK in Photoshop...

My question is, why wouldn't Photoshop open them? It didn't say what sort of document they were, only that they were the wrong sort...

Is there a way I can by-pass having to open them in Corel Photo Album and re-saving each one? The Corel program was only a trial and isn't operating fully, just the photo display and a few basic functions...Why did the images open in Corel and not Photoshop?

Thanks in advance for any help...

Perhaps the files didn't have the .jpg extension in the file name.
If so, just rename the files adding the extension to them.