Nikon coolpix files too large for our computer

we have a folder full of photo's on the cool pix chip which we can see only when camera is connected to computer, Unable to open after I transfer to a disc. LARGE picture files, 540 MB instead of the 1-2 on the other pictures.

What setting did we use when taking these pictures?
Can I re-size files without reducing quality?
We have Vista, home premium, is there recommended software to open such a large picture?

What happened?

Thanks in advance

What Coolpix camera are you using? And, are you sure that the files aren't videos?:confused:

I'd also like to know what camera you're using. Those do sound like video files. Can you check the extension on them? There's no way your camera is taking photos with files that big. Even RAW files aren't that big.