You're poured millions into R&D. You've cranked the hype machine into overdrive. And now you're on stage in front of millions of adoring fans.
And what do they do? They point and laugh. Yup, it's the 10 worst tech demo disasters
1. Lost in translation?
You're French cybersecurity expert Jeroma Athias and you want to tell people at a security conference about your product. So what do you do? Give a rambling, amateurish and incoherent presentation in dodgy English with crappy slides and classic 'is this on?' microphone weirdness.
What's worse is that his presentation is so simplistic it'd insult the intelligence of a 5-year-old. Who didn't even know what hacking was. Or a computer, for that matter.
2. Mind those stairs
This should be easy. You have to go on stage and walk up a few steps while a nice Japanese lady talks about the fact that you can walk up steps. Only you're a robot. And you're not actually looking where you going.
The funniest thing about this 2006 classic is the panic that ensues once the Honda Asimo falls over - as if placing screens between the robot and the crowd is going to save anyone any embarrassment whatsoever.
3. Run, take aim, shoot
Now technically speaking there's nothing wrong with this demo at all. It starts. It runs. It finishes. It's what happens in between that's truly unspeakable. Especially to the poor old lady who is one of the actors.
The Microsoft guy who introduces the clip tries to hide his obvious embarrassment with bluster and talk of 'going beyond'. Yes, it's Project Natal from CES 2006.
4. Moving right along...
Ah Windows Vista. The hype. The hype. Shame it didn't wow us in quite the way Microsoft intended, as these two chaps prove by plugging a flash drive into a laptop only to be greeted with the dreaded Blue Screen Of Death (BSOD). The Bill Gates-alike quips at the end "this is why we're giving away free versions." If only, eh?
5. A touching demo
In which a Japanese Microsoft guy attempts to demo Microsoft Surface Globe running on Windows 7. Live on TV. You can guess the rest. Makes us feel nostalgic for the old Tomorrow's World days.
6. Apple fail
Apple presentations are remarkable for their robotic slickness - but it wasn't always that way. This compilation of old keynotes shows Steve Jobs stumbling over his words, forgetting what key Apple technologies are and getting frustrated his Mac doesn't work properly. No wonder Sony's president is lost for words.
7. What goes up must come down
No field of human endeavour is without its fair share of mistakes. But few are as spectacular or as tragic as the ones that befall space travel. The European Space Agency must certainly rue the day its Foton-M1 space mission ended earlier than planned.
It lost a precious payload of expensive experiments, while on the ground one soldier was killed and several others were injured. The reaction of the crowd is particularly telling (warning: contains strong language).
8. Video? What video
This is every presenter's worst nightmare. You're in a room packed with your peers (in this case member of the local technology association) and every single thing you try to demo fails. Sadly there's no video, but the Seattle Times reported that plucky YouTube advertising director Suzie Reider kept going anyway, despite the fact that she couldn't show any actual YouTube videos. Apparently the venue's AV system worked perfectly well later on when local companies stepped up to collect their awards.
9. It's not shipping yet
Poor Microsoft. Another live TV demo. Another failure. This time it's for Windows '98 and Bill Gates covers his embarrassment by quipping "this must be why Windows '98 isn't shipping yet." Nice one, Bill.
10. And the world's most embarrassing tech demo failure goes to...
Steorn. Two years ago the Irish company invited journalists and fans to see it's amazing Orbo - a new kind of technology that promised free energy forever. Only the demo, which was supposed to take place at the Kinetica Museum in London, never happened.
Steorn MD Sean McCarthy initially blamed technical problems with the demo unit and the museum got closed for the day. The product was last demoed at the Waterways Visitor Centre in Dublin in February, only this time it was evidently battery-powered. So much for free energy.
Liked this? Then check out 10 embarrassing moments in tech
Sign up for TechRadar's free Weird Week in Tech newsletter
Get the oddest tech stories of the week, plus the most popular news and reviews delivered straight to your inbox. Sign up at http://www.techradar.com/register