Project breaks in transport?

I was making a basic Unity project for school on one of their MacBook Pros. When I needed to do some work at home, I zipped the file and put it in Google drive. When I got home, I booted up my Windows PC and dragged the zip out of the Google Drive app. I unzipped it and opened it up. Voila; all my assets were there, but the game world was completely blank, with no gameobjects. Only the camera and a directional light were there. What happened? Was data lost in the cross-platform transition? Was it the cloud? Was it the zipping process? Is this a common error that I can fix? I need this for tomorrow!

Thanks,

seabassfish

EDIT: I think I screwed with the metadata/didn't copy correctly, what is the right way to copy a project? http://answers.unity3d.com/questions/273912/moving-the-project.html gives confusing answers that might be pro-only. I only have personal edition.