Whenever I connected my iPhone to my PC running Windows XP I'd get window that'd pop up telling me that a camera was connected. It'd ask me what program I wanted to use for the camera. If you want to avoid this message, here's what you need to do.

Connect your iPhone and let the camera connected message come up.

Go to desktop and open up My Computer and navigate to your iPhone. Once you find it, right click on it and select Properties.

Click on the Events tab. In the Actions section, click the radio button for Take no action.

Click OK to save your changes. Once your changes are saved, your computer will no longer pop up a window telling you a camera is connected every time you connect your iPhone.