So your presentation is on a laptop that refuses to respond. It's a dead parrot. Your audience are waiting patiently. They are a group of experts, professionals. You are representing your Government and country overseas. So now what?
Rule 1: Laugh.
You'll feel better. The audience will be tense for you anyway.
Rule 2: Bring the audience in to help
They are part of the solution, your friends. Don't view them as the problem. Be authentic. What would you do if it was your family and friends in the audience?
Rule 3: Have a conversation
Yes, have a conversation. Powerpoints are boring anyway. Speak with passion and show them why what you are telling them is interesting and something they should care about. Why is it interesting and fascinating and surprising to begin with? If what you have to tell them isn't all those things, then ask yourself 'what is fascinating about this?'
Only dull people find dull what people say with interest and passion - so don't worry about it - if you are fascinated by your subject matter that's actually all that matters. But make sure you do take time to look at your subject matter with fresh exciting times. Familiarity breeds complacency. You forget the wonder of what you are doing and take the time to have that.
Then it really won't matter you don't have powerpoint...or your props fail, your set falls apart and hecklers disturb your flow...in fact you'll be better for it and your audience will be relieved.