Launch any one of your favorite browsers from the computer where you intend to upgrade your Canon camera software.
Enter this URL: https://www.usa.canon.com/internet/portal/us/home/support?tab=drivers
Enter your camera's name, such as "Powershot". A drop-down menu will appear, but continue typing with a space and then start entering your model number, such as S110. The "S" will give you another drop-down menu, which may contain your specific model. If not, keep typing until your model appears, and click that. Then click the "Get Drivers & Downloads" button following your entry. This is the URL I got for my S110:
https://www.usa.canon.com/internet/portal/us/home/support/details/cameras/point-and-shoot/advanced-cameras/powershot-s110/powershot-s110#drivers_downloads_tab
My Operating System was automatically detected. In my case, it was "Mac OS X Yosemite v10.10.5 (Detected)". Under "Recommended Downloads" it said there were none. Click on the "Software" button to the right, and you should get a list of components that you can apply individually. If NONE of them are later versions of what you already have, you're stuck. For example, on my Snow Leopard v10.6 system, there was nothing new for my S110. However, when I bought my new Macbook Pro in August of 2015, it came with Yosemite installed. I used "Migration Assistant" to bring across my Snow Leopard user-added software, which included the Canon Camera software. That was January 2014 code from the Canon Install CD. So for Yosemite, there were four (4) packages that I could apply:
For each on these,, I clicked the "SELECT" button, which now said "CLOSE", clicked the checkbox above the "Disclaimer" line, and then clicked "DOWNLOAD" to download the file. When done, I clicked "CLOSE", and went to the next entry, and repeated the above steps, until I had downloaded all the components I needed.
You can now "Quit" from your browser. Everything you need should now be in your default download folder. For me, that's my Desktop. It could be different for you, like a folder called "Download" in your $HOME directory. Now comes to fun part - actually applying the updates.
I found it was important to do these components in a particular order. 1) PhotoStitch; 2) Digital Photo Professional; 3) CameraWindow; 4) ImageBrowser EX. As you Finish each, DO NOT RESTART your computer; just Quit from the Installer. I saved the ImageBrowser EX for last because it wants you to connect your camera, and activate it with the "display pictures" button. For me on the S110, that's a red-dot button on the back next to the MENU button.
Before you turn on your camera, launch the Image Capture app (in /Applications), and then turn on your camera. Image Capture should detect your camera. Once its name appears in the left-panel, look at the very bottom left of that panel for a little button. Click it, and a menu of applications should appear, possibly with CameraWindow selected. Scroll to the top of the list, which should have a "No Application" choice, and select that. This will temporarily turn off auto-detect by CameraWindow, which is what was giving me "camera was not found" dialogs.
You can now Quit from Image Capture, and do the install for ImageBrowser EX. When done, Quit from the Installer, turn off and disconnect your camera, and do a standard Restart from your Apple menu. All of your new components will now be available, and your camera should be auto-detectable by CameraWindow again. That last install changes "No Application" back to "CameraWindow". You're done. For me, everything now worked.
Personally, I don't like auto-detect of the camera by CameraWindow, so I reconnected my camera, and turned it on with that back-button, and let CameraWindow run. When I Quit CameraWindow, ImageBrowser EX usually runs. I quit from that too. Finally, I launched Image Capture again, with my camera still turned on, and went to the lower-left button to display Applications, and selected "No Application", and Quit from Image Capture. I prefer to launch CameraWindow from the Dock at my discretion. But, that's just my personal choice. You're free to make your own choice.