Problem with PC Standalone application

Hi,

I’m very new to Unity, and using a Mac to code and test etc. I needed to send a test version to someone who uses a PC, so used the build settings to produce a standalone application for Windows. Unlike the Mac standalone which produces a single file, it produced a .exe file and a data folder. I zipped these up and sent them to him, he unzipped them, ran the exe and got an error something like “Error: failed to load mono.” It won’t run. Not being well versed in such matters, nor with a PC to play around with, I can’t figure out what I did wrong/he is doing wrong.
Any ideas?
Many thanks
Steve

either his security prevented mono from running (agressive antivirus that ask for it to be fine), he extracted it to the program files folder and didn’t start as admin (and you on osx can’t run it through mt.exe to give it elevated rights out of the box) or he has UAC interfering