Deb--you should be able to go into your computers set up and turn off the screen saver portion...there is a setable timer on that thing that usually will square you away....d
We did the same thing. Our gym walls are painted blue on the bottom 8 feet and yellow the rest of the way up. The movie was showing on both sections but it showed just fine. We also put the mic from the gyhm PA system next to the projector. The only hitch was someone had to wiggle the mouse every so often so the screensaver wouldn't come on. LOL
The movie was played in the gym on a projector. And about the sound a surround system was put and we needed help from the mic so that was put next to one of the speakers for extra volume.
I know that even if you dont have a screen, if you hang a white sheet it would look great on that as well.
I would just like to say that we just had our first Movie Night on Friday and it was great. There was a great turn out despite the horrible weather. The packet I received from you guys was great help and filled with great ideas. We had pizza and soda and candy for 30 minutes and the movie started promptly at 6:30 pm to avoid staying at school so late(especially with little ones). I'm looking foward to next year and taking charge again.