In the root directory with the 3ds Max executable is a file PLUGIN.INI. This file contains a one-line entry for each plug-in search location. When 3ds Max begins execution it searches each path listed in this file looking for plug-in DLLs. When a plug-in DLL is found it is loaded. This system allows developers to store their plug-ins in whatever sub-directory structure they wish. The format for the PLUGIN.INI file is:

DescriptiveText=SearchPath

Here's what a sample PLUGIN.INI might look like:

Standard3ds Maxplugins=C:\3DSMAX\STDPLUGS
Miscellaneousfree plugins=C:\3DSMAX\MISCPLUG

From the 3ds Max File menu is a choice Configure Paths. The dialog page for plug-ins lists the paths defined in PLUGIN.INI. The user may use the interactive tools in this page to edit PLUGIN.INI and add or remove search paths. Manual maintenance shouldn't be required often, however, since a plug-in's install routine can automatically write a string to the PLUGIN.INI file that contains all the information required after creating the sub-directory and copying its files into it. Mostly, manual maintenance will be used to create directories for freebie plug-ins, and to de-install directories for plug-ins that are no longer used.