"Canon Raw Coder"? That sounds like Canon software, which would not be Adobe Photoshop related.
Hello, in order to get help, please share contents of help>System info... so that we'll know in one swoop the version of Camera Raw, Photoshop, windows/mac, etc.
Also, please tell us what camera took the pictures.
Adobe photoshop version 12.0
Windows Vista 32-bit
Camera Raw 6
I bought the Canon EOS 1100D last year.
Hope this info helps.
Photoshop and Camera Raw are not updated to their latest versions? Help>Update
You need at least Camera Raw 6.4 to open the files: http://helpx.adobe.com/creative-suite/kb/camera-raw-plug-supported-cameras.html.
But as said earlier, it might not be Photoshop related.
I believe this message occurs when Windows Explorer is opened on a folder of CR2 files and the installed Canon RAW codec is too old to display the thumbnails. It is my experience that there is also a link in the message where to download the latest Canon RAW codec. It may be that Canon has not updated their codec to include support for the 1100D or it may be that there is a newer one that needs to be installed.
Why would this message occur when using PS. Windows Explorer would be called upon to show thumbnails if you use File / Open in PS and browse to a folder of files, or if you have Windows Explorer directly open on a folder in preparation for using right-click / Open With… / Photoshop.
How to fix it would be to either install a newer Canon RAW codec that supports the 1100D, or use Bridge to browse for your photos, once you have installed a Camera Raw plug-in that is new enough to support the 1100D.