Just thought I'd throw in my 2 cents.
I don't have any direct experience with doing exactly what you are asking about. But I have run into issues that could be embarrassing in a public forum.

Make sure the PC or Laptop has more than enough CPU power, RAM and HDD speed to handle the entire presentation without any jerks or delays from one scene to the next.
Make sure the computer is physically secure so that somebody doesn't try to play with it before the presentation. Practical jokes or a small unattended child could be a show stopper and bosses won't be pleased.
Most people struggle with laptop touch pads, go for a real mouse so you can fix things quickly if something goes wrong.
These issues alone may justify burning the presentation to a Blu-Ray or HD/DVD and play it that way. Vastly reducing Murphy's Law. Investors like to see things go without a hitch and that other attendees are impressed. Nobody will care why you have glitches, they will just remember you did. There is something magical about dropping a disk in a player that was computer generated on site that lets people's imaginations run wild as to what was used to create the show. Let them think that it took a room full of computers working for a month to create it. You become the wizard in their minds.

The audio needs to be much louder than you would expect if it is going to fill a large room clearly. When I got married recently I tried to use my home surround sound system to play music in the dance hall. Although the system was loud as heck in our living room at home, the dance hall was much much bigger than we anticipated and at full volume it sounded more like a pocket radio across the room. I know that PA systems can be rented and sized for the room. Since you will want to grab the emotions of the audience you will likely want some musical score in your presentation that is dramatic. You'll want to do some tests before hand to make sure the sound system and music gives you the results you want. Things that sound great on a pair of crappy computer speakers may sound very different on a quality sound system in a different environment. You may also want several speakers placed around walls of the room so that you can have the volume at a decent level everywhere. It can be a problem if you only have speakers located next to the display because they will have to be turned up to excessive volume to reach the opposite end of the room. What sounds like a weak sound system across the room could actually be at hearing damage levels up close. Think about theaters. They place speakers all around the room because if they didn't, nobody in the front row would be able to hear after the movie.

Others may have more specific experience and can guide you better to exactly what you need.