When using the JPEG file type on a Windows computer, you may notice that the thumbnail does not match the actual image it is representing. This problem is specific to the JPEG file type and does not happen with other file types. This problem is easily resolved by following the instructions below.
This Microsoft article is for Vista specifically, but it applies to any version of Windows after Vista. http://support.microsoft.com/kb/928572/
Windows Vista/7/8/10 - Open the Disk Cleanup tool. It's located under All Programs > Accessories > System Tools > Disk Cleanup.
Once the Disk Cleanup tool is open, select the option for Thumbnails and click the button labeled Clean up system files. Click "OK" to close the dialog once the cleanup is completed.
Windows XP - Right click the image file and choose Refresh Thumbnail.
Windows will delete and rebuild your thumbnail cache correcting the issue.