Harrison, Like many Windows program that modify an environment variable (in this case the path), the MPLABC Demo installation forces a reboot to reset the environment variable for later use. The install program adds the directory chosen for MPLABC to your path in the AUTOEXEC.BAT file. Pete Pete.Brink@Microchip.com ______________________________ Reply Separator _________________________________ Subject: installation caused reboot Author: Harrison Cooper at Internet_Exchange Date: 6/5/96 3:19 PM I downloaded MPLab 3.09 and installed the main file, help file and then the C demo program, where upon click'en on OK at the end caused windows to exit (how nice) and then reboot the machine. Quite strange...