Also open a new tab when restoring previous windows and tabs: registry value NewTabOnRestoreComputerHKLM\Software\Policies\Mozilla\Firefox\Homepage

Policy ID: Homepage_NewTabOnRestore
Scope: Computer Configuration, User Configuration
Supported on: Firefox 154 or later
Source: Mozilla Firefox Policy Templates (version 8.3)
Category: Mozilla › Firefox › Home page

Registry

NewTabOnRestore

REG_DWORDComputerUser

…\Software\Policies\Mozilla\Firefox\HomepageHKLM\Software\Policies\Mozilla\Firefox\Homepage Current key
HKCU\Software\Policies\Mozilla\Firefox\Homepage

Enabled value: 1
Disabled value: 0

Apply with .reg · CMD · PowerShell

ComputerMachine-wide setting

.reg

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\Software\Policies\Mozilla\Firefox\Homepage]

; Options (use only one)
; Enabled
"NewTabOnRestore"=dword:00000001
; Disabled
"NewTabOnRestore"=dword:00000000

CMD

:: Options (use only one)

:: Enabled
reg add "HKLM\Software\Policies\Mozilla\Firefox\Homepage" /v "NewTabOnRestore" /t REG_DWORD /d 1 /f
:: Disabled
reg add "HKLM\Software\Policies\Mozilla\Firefox\Homepage" /v "NewTabOnRestore" /t REG_DWORD /d 0 /f

PowerShell

# Common: create the key
New-Item -Path 'HKLM:\Software\Policies\Mozilla\Firefox\Homepage' -Force | Out-Null

# Options (use only one)
# Enabled
New-ItemProperty -Path 'HKLM:\Software\Policies\Mozilla\Firefox\Homepage' -Name 'NewTabOnRestore' -PropertyType DWord -Value 1 -Force | Out-Null
# Disabled
New-ItemProperty -Path 'HKLM:\Software\Policies\Mozilla\Firefox\Homepage' -Name 'NewTabOnRestore' -PropertyType DWord -Value 0 -Force | Out-Null

UserPer-account setting

.reg

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Policies\Mozilla\Firefox\Homepage]

; Options (use only one)
; Enabled
"NewTabOnRestore"=dword:00000001
; Disabled
"NewTabOnRestore"=dword:00000000

CMD

:: Options (use only one)

:: Enabled
reg add "HKCU\Software\Policies\Mozilla\Firefox\Homepage" /v "NewTabOnRestore" /t REG_DWORD /d 1 /f
:: Disabled
reg add "HKCU\Software\Policies\Mozilla\Firefox\Homepage" /v "NewTabOnRestore" /t REG_DWORD /d 0 /f

PowerShell

# Common: create the key
New-Item -Path 'HKCU:\Software\Policies\Mozilla\Firefox\Homepage' -Force | Out-Null

# Options (use only one)
# Enabled
New-ItemProperty -Path 'HKCU:\Software\Policies\Mozilla\Firefox\Homepage' -Name 'NewTabOnRestore' -PropertyType DWord -Value 1 -Force | Out-Null
# Disabled
New-ItemProperty -Path 'HKCU:\Software\Policies\Mozilla\Firefox\Homepage' -Name 'NewTabOnRestore' -PropertyType DWord -Value 0 -Force | Out-Null