Require Ctrl+Alt+Del before signing in — via Microsoft Learn

Group Policy

Open gpedit.msc (Pro, Enterprise and Education only) and go to:

Computer Configuration > Windows Settings > Security Settings > Local Policies > Security Options > Interactive logon: Do not require CTRL+ALT+DEL = Disabled

Registry equivalent

Double-click a .reg file and confirm to merge it. Right-click → Edit first if you want to read it, which is always a good idea with any .reg file from the internet.

Apply

Windows Registry Editor Version 5.00

; Oddbyte.Me: Require Ctrl+Alt+Del before signing in

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System]
"DisableCAD"=dword:00000000

Undo

Windows Registry Editor Version 5.00

; Oddbyte.Me: undo Require Ctrl+Alt+Del before signing in

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System]
"DisableCAD"=dword:00000001

Same thing from a command prompt

Run in an administrator Command Prompt or Terminal.

reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System" /v "DisableCAD" /t REG_DWORD /d 0 /f

Undo:

reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System" /v "DisableCAD" /t REG_DWORD /d 1 /f

On standalone PCs the default is "Do not require" (DisableCAD = 1), which the undo restores. The value name is a double negative: 0 means Ctrl+Alt+Del is required. Microsoft's security baseline expects it to be required.