Save Active Project only
Supported on: At least Windows Server 2008 R2 or Windows 7
Registry
HKCU
software\policies\microsoft\office\16.0\ms project\options\save Value name: automaticsaveoption
Enabled: automaticsaveoption = 1
Disabled: automaticsaveoption = 2
Description
Saves only the active project at the interval you specify. This setting is only used by Project if Auto Save is turned on. If you enable this setting, Project will only save the active project at specified intervals. If you disable or do not configure this setting, the user's default setting is used.