The same kind of error dialog is also discussed in this thread: http://developer.tobii.com/community/forums/topic/installer-were-sorry-an-error-occured-installing-tobii/
If it is not a problem with a virus scanning process interfering with the installation, it might be due to problems with the Windows Installer not running or having corrupted registry settings. Other causes might be installing to an encrypted folder or to a substitute drive. See the other thread and linked Windows KB articles there for more information on these possible solutions.