I have tried the delete functions in Photoshop CS2, CS5, Bridge, My Computer and Windows Explorer, but in all those programs I get an error message when I try to delete one or more CR2 files. I get two kinds of messages. They say that either: A. I don't have the necessary permissions - but, in "Properties," none of the files are read-only and all admins are allowed, or B. That the file is in use by another person or program. But no other program is open.
I'm at wit's end.
What operating system are you using? One of the newer ones (Vista or Windows 7) that has UAC? UAC essentially sets things up so you're NOT the admin normally. You need to request special permission to do admin things (e.g., start Explorer with Run As Admin, or just shut off UAC).
How do you get those files onto the disk from your camera?
Do you have any 3rd party codecs to make thumbnails for your raw files in Explorer?