I was recording and video on my phone when the battery died, how can I recover the video file?

I read the other questions I could find. This is completely different. My question is **NOT about finding the file**. **The file is on my phone**. It is the correct size. It shows as an mp4 with the right icon on windows. It has an mp4 suffix. It's 22+MB so it's there. It will not play in MS Media Player or with VLC player. It doesn't show up on the phone itself in the gallery, but it's there when I connect the phone to my laptop. I was recording the video, my battery died, the phone shut off while I was recording. There are many programs on the internet that claim to fix video files, but I'm afraid to download any of them because I do not want to get a virus. My phone is an HTC EVO 3D. My carrier is Sprint. My laptop is a Samsung running Windows 7. I recorded it regular mode not in 3D mode. How do I **play** this file? How do I **fix it**? What should I do? If there's a piece of software I should download to my laptop to fix it, what is a good reputable site where I won't get malware/virus?