When they saved the powerpoint presentation, they should have used the File, Pack and Go menu. This downloads the presentation with the PP Viewer. This allows you to run the presentation on any machine.
Ask them to do it again using the above technique.
Then run it on the machine you are going to use with the projector and make absolutely sure that it looks OK, before you go live.
Many people have been caught out making a presentation without making sure what projector they are using and finished up with crap slides, becuase the projector is an old one and cannot deal with the latest technologie.