Why are my iPhone videos not in sync with audio when moved on to my laptop?

So when move videos i take on my iPhone 4s or iPod 4th gen to my laptop which is running Windows 7, all of the videos are not in-sync with the audio it was recorded with. They all work fine on the devices but never when I move them to my laptop. All I do is drag and drop the video files from the iPhone to my laptop. I do not use any converters.Am I doing something wrong?

It could easly be that apple runs there own media software and that your laptop doesn't have that software or isn't compatible also windows 7mis an o.s. And has no effect on your media most of the time

Use ITunes to import the files.