Look in to the maxstart.max file.
https://knowledge.autodesk.com/support/3ds-max/learn-explore/caas/CloudHelp/cloudhelp/2023/ENU/3DSMa...
When you start 3ds Max, several auxiliary files load, setting things like program defaults and UI layout. You can even create a scene, named maxstart.max, that automatically loads when you start or reset 3ds Max. In some cases, 3ds Max updates files when you change settings and when you quit 3ds Max.
Note: 3ds Max comes with several different Market-Specific Defaults. These set different program defaults on startup, based on the type of files you expect to work on most often. You can load the preset defaults that come with 3ds Max, or you can create your own.
In general, you don't need to work directly with the auxiliary files, but it's good to know about them. Among the auxiliary files 3ds Max uses are:
