If you have a Canon camera, you have to install a third-party software that support displaying CR2 (Canon RAW format) files.

Few days ago, I found that it’s not necessary because Canon provide a “codec” that help displaying CR2 file right with Windows Photo Viewer and thumbnail generation. You can download it from this link then install in your computer.

Download link from Canon USA (updated 11/7/2010: link missed by Canon)

http://majorgeeks.com/Canon_RAW_Codec__d5816.html

After installed, this codec will help Windows generate the thumbnail for each CR2 file when you view them on Windows Explorer. It also helps Windows Photo Viewer display the image correctly. Is it good when you do not need to use 3rd party software anymore in order to view your shots?

PS: Known issue with the codec: Windows 7 64-bit CANNOT generate the thumbnail in Windows Explorer.