Can I resume the voting after I’ve closed down the slide show without completing all the question slides?

Yes, PowerCom has built-in intelligence that remembers which slide you polled last. Just start your PowerPoint presentation again and PowerCom will ask if you want to restart, or continue from where you left off, or start the slide show from the current slide (just like PowerPoint depress shift + F5) and select “continue the session from the current slide” to continue polling from your last polling slide.