There is a known Windows 7 rotation issue with portrait photos taken with the iPhone 4 and 4S. Unlike with the 3G or 3GS, photos taken in portrait mode on the iPhone 4 and 4S do not auto-rotate when imported in to Windows 7. This is the case: (i) whether you sync your photos via iCloud; or (ii) whether you physically import them via USB; even when you explicitly set the Windows import utility to auto-rotate them on import. The issue is being discussed here, here , here and here on the Apple support forums and here on the Microsoft support forum.
To make matters worse, a good portion of these photos end up locked in such a way that you cannot subsequently rotate them with the various photo rotate tools built in to Windows 7 (see error message in the image above).
While there are any number of hacks and workarounds discussed in the Apple support forums, I found the easiest solution is to use the free JPEG Lossless Rotator app. When you install the app, make sure you select the ‘Integrate JPEG Lossless Rotator with shell’ option (circled in red below).
After installation, when you right click on a locked iPhone 4/4S image (or group of images) in Windows Explorer, you’ll have two new rotate options (circled in green below):
Without JPEG Lossless Rotator, the rotate functions built in to Windows Explorer (circled in red above) often do not work. You’ll hear a Windows 7 something’s-gone-wrong ‘clank’ noise and the ‘Rotation’ error popup shown above will appear . If, however, you choose one of the new ‘Lossless Rotate …’ options (circled in green above) the image (or group of images) always rotate as expected. Presto! Easy as pie. And, as the app’s name implies, without any loss in image quality.