Hi Becstarr
To see the files under native windows programs you need the windows Codecs otherwise you will only be able to open them in DPP, can't say I had the problem of not being able to view any images in DPP other than when they have been processed in another application and not flattened out of Photoshop or similar.
Here is a link...
http://support-au.canon.com.au/conte...200059703.html
Canon Blurb...
Canon RAW Codec is a plug-in software that enables the import and display of Canon RAW image files when installed in Windows Vista (including SP1)/Windows XP SP2 and Windows XP SP3(*).
* To use the software with Windows XP SP2 and Windows XP SP3, application software that supports WIC (such as Microsoft Windows Live Photo Gallery) will be required.