How to find or change the Auto Backup location for 3ds Max files

3ds Max Auto Backup files can be saved automatically to a preferred folder location using the Configure User Paths window.

1. To change the location that the backup files are saved to:
2. Go to Customize menu.
3. Choose Configure User Paths. In the File I/O tab, select the “AutoBackup” option listed.
4. Press the Modify button.
5. Choose the preferred folder or location for the backup files to be stored.
6. Press OK to keep the changes.

Note: Configured user paths will be saved per installation not per scene file.

Source: https://knowledge.autodesk.com/support/3ds-max/troubleshooting