LaserWriter 8.6 is not supported on Mac OS 8. Documentation that accompanies the LaserWriter 8.6 installer named "Before You Install LW 8.6" more clearly states: "This software will only install on Mac System 7.6.1, Mac OS 8.1, and Mac OS 8.5 or later."
Because the printer software is not supported on Mac OS 8.0, you will receive this message if you attempt to install LaserWriter 8.6 onto Mac OS 8.0 : "This installer is incapable of updating System 8.0. Please update to System 8.5 first. Sorry!"
Though Mac OS 8.5 has many benefits over older versions of the Mac OS, the driver could also be installed on Mac OS 8.1. Should you be using Mac OS 8.6 or later, however, the recommended and supported version of the LaserWriter driver for that OS is the version of the LaserWriter driver that ships with it.