Film - Problem With Animation

We had finished our animation a few weeks ago. However we have had a big problem with it. Once we had completed our animation on the PC we imported it on a memory stick so that we could transfer it onto the MAC. When to put the memory stick into the MAC it would not upload the animation because it was in the wrong format. We decided to go the IT technician and see if they could change it into a format which would work with the MAC computer. A few days after we went to get the memory stick as the technician had said that they had put the animation in a suitable format to work on the MAC. We then put the memory stick into the MAC and the animation seemed to import onto the computer. The animation was now on the computer in which we dragged it onto the desktop. However the animation was still unable to upload on I-Movie. Again we went back to the IT technician for them to convert the animation in a suitable file that works with I-Movie.