There are many, many articles and blog posts out there devoted to this topic – but none had worked for me. Below is my eventual solution (that finally allowed me to transfer 1326 pics & vids collected over 3 years), which is pieced together from the different suggestions.
First, the specs I was working with…
Windows OS: XP
iTunes: Not installed.
1) Make sure to unlock your iPhone first (enter the passkey), and then connect it via USB to your computer.
2) Check if your iPhone has appeared directly as a device in My Computer/Windows Explorer. Can you access and copy your photos from here? If not, move to Step 3.
(For me, the iPhone would always be “empty” when I clicked on it)
3) Access the Scanner and Camera Wizard via Start > All Programs > Accessories > Scanner and Camera Wizard. Can you access and copy your photos using the Wizard tool? If not, move to Step 4.
(For me, the Wizard always reported that there were no pictures on the ‘camera’)
4) On one of the Apple support pages, it was suggested that Windows Live Photo Gallery or Adobe Photoshop Elements could also be used to import pictures. I went for the free Windows option, which I downloaded from here. The Windows Live installer will prompt you to install multiple apps – but Photo Gallery is all you need.
5) Go to File > Import from a camera or scanner and select your iPhone.
(For me, on first use, Photo Gallery acted the same as the Scanner and Camera Wizard, in that it detected my iPhone but could not access any pictures. At this point, I disconnected the iPhone from the computer, entered my passkey once again and then reconnected the iPhone to the computer)
6) Eureka. On the second try, Photo Gallery was able to detect all of my pictures and videos – and gave me options on how to import, create groups, delete the pictures from the iPhone afterwards, etc.
* For ease, you may wish to disable the passkey functionality on your iPhone permanently during this process – but make sure to re-enable it once you’re finished.
* A number of forums mention installing or uninstalling an Apple driver in Device Manager. I did not have this driver installed.
* You may need to disconnect and reconnect your iPhone a number of times, and always make sure your iPhone is unlocked before attempting to import. Unfortunately trial and error seems to be the main course of action!