Windows Thumbnails Wont Appear?

Ed B. from Long Island, New York writes:

" I enjoy your newsletters very much! They're very informative and easy to read. I've seen a lot of other similar newsletters, and yours definitely rank among the very best of them.

My question: I use Windows XP Pro and save a lot of graphics on my hard drive (the usual .GIF, .JPG. and some .BMPs). When I view the folders in Windows Explorer (thumbnail or filmstrip mode), some of the files don't show the thumbnail preview image, and Windows tells me No Preview Available.

I don't change the file extensions when I save the graphics, so why does Windows show the preview thumbnail on some and not others?? My techie friends are all stumped. Any ideas? "

My Response:I have XP Pro, too, and tried everything I could to reproduce Ed's problem ... but could not.

My best guess is that Ed has accidentally saved some images with the wrong file extension. I have done this in the past when converting an image format from .JPG to .GIF with Paint Shop Pro (PSP). Many times, I save the file name and include the new .GIF extension, but forget to change the format under the pull-down menu.

PSP then saves the file as a .JPG, even though I've inadvertently changed the file extension to .GIF. Saving an image with the incorrect file extension would definitely make the file type unreadable by Windows (assuming that Windows uses file extensions to measure the type readability).

Anyone have a better solution or suggestion? Email me.

Update 2003/02/13: This article has been updated. Click here to read!