Converting to MP4 in iMovie

Hello!

I'm working on a couple of video projects for work, and I always use iMovie. These movies need to be playable in Powerpoint on Windows 8.

The videos I have made are .MOV, but they won't play when I transfer them across to Windows. I looked up the solution, and I need to convert to MP4. Many web pages tell me I can export from iMovie to .MP4, but I can't seem to figure it out - I can only export as .MOV.

I have managed to convert to .M4V using Quicktime, but the quality is nowhere near acceptable. Can someone tell me how to get a .MP4 file from iMovie please?

Using a MacBook Pro, and iMovie Version 10.0.6

Thanks in advance!