I have the same problem but instead of instant reboot my laptop BSOD's with the IRQ_LESS.... The protection scan doesn't show up before the crash.
I encountered the problem a year ago on my desktop PC but I tried installing it again after the issue with the laptop and it worked this time around.
I have Nvidia Nforce 4 chipsets in both my laptop and desktop and suspect it may be inconsistencies with SF3 and nvidia IDE/SATA drivers. Originally I played the game with a Nforce2 based system but it didn't include nvidia SATA.