Hello,
I have the same notebook with preinstalled SUSE Linux Enterprise 11 SP2 (Probook 4540s). Unfortunately You shouldn't reboot notebook before the presentation will end. There was some information on presentation like "Do not turn of laptop before end ... etc" but quite hard to read.
But there are some good information - Your notebook has a recovery image created (I think successful) on one of partition on Yours hard drive. I recommend to start whole process again - to do this, on the boot screen press "Escape" key (when You see HP logo) and choose option like "Recovery ..." probably F4 button.

Sorry for my language.