Hi Bruce, Yuni, Everyone, The main issue is that the batch files to run the Ifeffit programs have SET IFEFFIT_DIR=C:\Program Files\Ifeffit which is correct for Win NT, 2000, XP, but fails on 95/98/Me because of the space in 'Program Files'. The problem can be avoided in one of two ways: 1. change the *.bat file to say SET IFEFFIT_DIR="C:\Program Files\Ifeffit" This appears to work on 95/98/Me but not 2000/XP!! 2. install Ifeffit into a directory without a space in the directory name, such as C:\ifeffit The reports I hear are that both of these work. I'm putting the finishing touches on the windows installer for 1.0077. I'm not sure I can fix this problem for this round, but I'll look into a way of auto-detecting 2000/XP v 98/Me. --Matt