Hide all Office-provided templates on the Office Start screen and in File | New: registry value disableofficetemplatesUserHKCU\software\policies\microsoft\office\16.0\common\general

Policy ID
L_DisableOfficeTemplates
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 Office 2016 › Tools | Options | General | Web Options...

Registry

disableofficetemplates

REG_DWORDUser
Enabled value
1
Disabled value
0
Apply with .reg · CMD · PowerShell
.reg
Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\common\general]

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

:: Enabled
reg add "HKCU\software\policies\microsoft\office\16.0\common\general" /v "disableofficetemplates" /t REG_DWORD /d 1 /f
:: Disabled
reg add "HKCU\software\policies\microsoft\office\16.0\common\general" /v "disableofficetemplates" /t REG_DWORD /d 0 /f
PowerShell
# Common: create the key
New-Item -Path 'HKCU:\software\policies\microsoft\office\16.0\common\general' -Force | Out-Null

# Options (use only one)
# Enabled
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\common\general' -Name 'disableofficetemplates' -PropertyType DWord -Value 1 -Force | Out-Null
# Disabled
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\common\general' -Name 'disableofficetemplates' -PropertyType DWord -Value 0 -Force | Out-Null