HI! I just got off the phone with Canon as I was having a problem with my Rebel XT. According to them, Camera Window isn't used by the XT, only by PowerShots. Since I had previously had a couple of PowerShots, Camera Window was included with all of the software I had installed on my XP PC. I had previously always used a card reader which instantly opened ZoomBrowser, so I never even opened Camera Window. Since today, I have to go directly from the Rebel to the PC and kept getting that "not compatible" message. Apparently, if I'm no longer using the PowerShots my best course of action is to uninstall Camera Window.