Sd600 digital camera trouble downloading pics to... (by 2 users)

I have a new sd600 camera and I have consistently had trouble downloading images to my DELL PC laptop (I have windows xp). There seems to be a problem with detecting the connecting to the computer through the usb port but I knwo that I didn't need to download any usb drivers since I have windows xp. I was only able to download pics one time and that was after I continuously tried opening the camera window and unplugging and replugging the usb cable into the computer. Now I can't download pictures at all, and for some reason every time I plug the camera into the computer with the cable, adobe photoshop opens up instead of the camera window and it can't detect the camera. I have tried opening the camera window manually and it either doesn't open or it gives me a message saying the device is not connecting. I have tried everything from uninstalling to reinstalling the software and it still doesn't work. Any ideas?