I tried downloading Handbrake, got an error message when I tried to run it: "Handbrake.exe is not a valid Win32 application"

I tried saving a video as an .exe instead of an .avi. I was able to get it to play in Media player on another computer, but the size of the viewing area is smaller, and the file size is x2.25 larger. At least it plays; now to see if it will all fit on a dvd.

Thanks for the responses, I wasn't planning on spending so much time on this today, but I need it in the morning.