Hi Andrew, Hmm, not sure what's going on. It worked for me on one system, but I'll try this on another machine later today. I think the key is to have the folder with ifeffit_12.dll in your PATH. You say you had to edit the use_ifeffit.bat file -- did this have the incorrect paths? A reasonable workaround (and perhaps the distribution should do this) is to copy the dll to C:\Python27\DLL. The trouble with that is that many of the PGPLOT environmental variables might not be set correctly.... but that just means plotting won't work, which might be acceptaable. -Matt On Jul 14, 2011 9:59 AM, "Andrew Korinda" wrote: