After I record it, send it to my laptop, then go to add the video file to WMM and it says I cant Im pretty sure I used to use iPhone videos on WMM a while ago. 
ThanksThere's an easy way to go around this, actually. What's the video file that your iPhone video outputs into? MP4? AVI? Movie Maker is compatible with a varying amount of video files. What I would do in your situation is use an online video converter. The site I use for these types of things is literally called 'onlinevideoconverter.com' I don't know if I can necessarily link you, but these sites really help out in a pinch. And with no cost to your video quality. I would convert it to MP4, if your WMM is compatible with that. If not, I can guarantee AVI will probably work.
So does converting video files from 1 format to another, and even another again not effect the video playback quality at all?
I don't believe so. A part of my channel is reaction based videos, so I do quite a bit of converting. I convert my video files and my audio files to specific types, and it hasn't caused any noticeable difference. Now, because you said 'at all', I will clear up that it is impossible to convert videos without losing quality, but that's to be expected. When you convert one format to another, the video file will be processed and compressed. Thus, the quality of video will be slightly lost. But, converting video files is a necessity for many content creators, so no one really cares on the off-chance that they do notice something a TINY bit off. AND If you convert the video file to MP4 or WMV, I can guarantee you won't even notice the difference. The loss in quality would be that minimal. But everything on YouTube's really trial and error.Thanks