Previous-version file formats: registry value legacyfilesUserHKCU\software\policies\microsoft\office\16.0\ms project\security

Policy ID: L_Legacyfileformats
Scope: User Configuration
Supported on: At least Windows Server 2008 R2 or Windows 7
Source: Microsoft 365 Apps / Office Administrative Templates (version 5568.1000)
Category: Microsoft Project 2016 › Project Options › Security

Registry

legacyfiles

REG_DWORDUser

HKCU\software\policies\microsoft\office\16.0\ms project\security Current key

Enabled value: Depends on the option value
Element: -

Options
Item	Stored value
Do not open or save	0
Prompt when opening and saving	1
Allow opening and saving	2

Apply with .reg · CMD · PowerShell

.reg

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\ms project\security]

; Options (use only one)
; Do not open or save
"legacyfiles"=dword:00000000
; Prompt when opening and saving
"legacyfiles"=dword:00000001
; Allow opening and saving
"legacyfiles"=dword:00000002

CMD

:: Options (use only one)

:: Do not open or save
reg add "HKCU\software\policies\microsoft\office\16.0\ms project\security" /v "legacyfiles" /t REG_DWORD /d 0 /f
:: Prompt when opening and saving
reg add "HKCU\software\policies\microsoft\office\16.0\ms project\security" /v "legacyfiles" /t REG_DWORD /d 1 /f
:: Allow opening and saving
reg add "HKCU\software\policies\microsoft\office\16.0\ms project\security" /v "legacyfiles" /t REG_DWORD /d 2 /f

PowerShell

# Common: create the key
New-Item -Path 'HKCU:\software\policies\microsoft\office\16.0\ms project\security' -Force | Out-Null

# Options (use only one)
# Do not open or save
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\ms project\security' -Name 'legacyfiles' -PropertyType DWord -Value 0 -Force | Out-Null
# Prompt when opening and saving
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\ms project\security' -Name 'legacyfiles' -PropertyType DWord -Value 1 -Force | Out-Null
# Allow opening and saving
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\ms project\security' -Name 'legacyfiles' -PropertyType DWord -Value 2 -Force | Out-Null