When working with nested Remote Desktop Protocol (RDP) sessions, particularly in Windows Server 2008 R2 environments, developers often encounter the frustrating limitation where keyboard shortcuts like Ctrl+Alt+Del fail to propagate beyond the first-level session. This becomes especially problematic when:

• Managing virtualized development environments
• Debugging multi-tier applications
• Automating server maintenance tasks

The default Windows behavior intercepts Ctrl+Alt+Del at the OS level for security reasons. In nested RDP scenarios:

Client Machine (Win7) → RDP Session1 (Server2008R2) → RDP Session2 (Server2008R2)

Traditional solutions like Ctrl+Alt+End only reach Session1 because:

1. The key combination is captured by the local OS first
2. RDP clients handle the translation differently at each level
3. Windows security architecture prevents direct forwarding

Here are three technical solutions with implementation examples:

1. Using the On-Screen Keyboard (OSK)

While not ideal for automation, this works for manual operations:

# PowerShell command to launch OSK in Session2
Invoke-Command -ComputerName Session2 -ScriptBlock { osk.exe }

2. Remote Desktop Services Manager

For administrative access:

1. Open cmd.exe in Session1
2. Run: mstsc /admin /v:Session2
3. Use Ctrl+Alt+End in the new window

3. Custom PowerShell Script

Create a forwarding script:

# SendCAD.ps1
$session = Get-RDUserSession -HostServer Session1 | Where-Object {$_.UserName -eq "admin"}
Invoke-RDUserLogoff -HostServer Session1 -UnifiedSessionID $session.UnifiedSessionId -Force

For programmatic solutions requiring API access:

// C# P/Invoke example
[DllImport("user32.dll")]
static extern void keybd_event(byte bVk, byte bScan, uint dwFlags, UIntPtr dwExtraInfo);

public static void SendNestedCAD()
{
    // Simulate Ctrl
    keybd_event(0x11, 0, 0, UIntPtr.Zero);
    // Simulate Alt
    keybd_event(0x12, 0, 0, UIntPtr.Zero);
    // Simulate Del
    keybd_event(0x2E, 0, 0, UIntPtr.Zero);
    // Release keys
    keybd_event(0x11, 0, 0x0002, UIntPtr.Zero);
    keybd_event(0x12, 0, 0x0002, UIntPtr.Zero);
    keybd_event(0x2E, 0, 0x0002, UIntPtr.Zero);
}

For permanent configuration changes:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Keyboard Layout]
"Scancode Map"=hex:00,00,00,00,00,00,00,00,02,00,00,00,1d,38,53,e0,00,00,00,00

---

When working with nested Remote Desktop Protocol (RDP) sessions on Windows Server 2008 R2 (with a Windows 7 Enterprise client), sending Ctrl+Alt+Del to the innermost session presents a unique technical challenge. The standard key combinations either get intercepted by the first-level session or fail to propagate entirely.

The conventional approaches don't work in nested scenarios:

• Ctrl+Alt+End: Only reaches the first RDP session
• Ctrl+Alt+Shift+End: Often gets blocked by RDP redirection
• On-screen keyboard: Doesn't solve programmatic needs

Here are three technical approaches to solve this problem:

1. Using PowerShell Remoting

This script executes Ctrl+Alt+Del directly on the target machine:

# Requires PowerShell Remoting enabled on target
$session = New-PSSession -ComputerName NESTED_SERVER
Invoke-Command -Session $session -ScriptBlock {
    $signature = @"
    [DllImport("user32.dll")]
    public static extern void keybd_event(byte bVk, byte bScan, uint dwFlags, int dwExtraInfo);
"@
    $keyboard = Add-Type -MemberDefinition $signature -Name Keyboard -Namespace Win32 -PassThru
    # Simulate Ctrl+Alt+Del
    $keyboard::keybd_event(0x11, 0, 0, 0) # Ctrl
    $keyboard::keybd_event(0x12, 0, 0, 0) # Alt
    $keyboard::keybd_event(0x2E, 0, 0, 0) # Del
    Start-Sleep -Milliseconds 100
    $keyboard::keybd_event(0x2E, 0, 2, 0) # Del release
    $keyboard::keybd_event(0x12, 0, 2, 0) # Alt release
    $keyboard::keybd_event(0x11, 0, 2, 0) # Ctrl release
}
Remove-PSSession $session

2. RDP File Configuration

Modify your RDP connection file to enable special key redirection:

enablecredsspsupport:i:0
redirectkeyboard:i:1
disablectrlaltdel:i:0
alternate shell:s:rdpinit.exe

3. AutoHotkey Script

Create a script that sends the sequence to the specific window:

#IfWinActive ahk_exe mstsc.exe
^!Del::
{
    ControlSend,, ^!{Delete}, A
    return
}
#IfWinActive

For session management without the key sequence:

tscon %SESSION_ID% /dest:console /v

Remember that sending Ctrl+Alt+Del programmatically has security implications:

• Credential Security: Disable credential delegation in group policy
• Audit trails: Log all remote security sequence invocations
• Network isolation: Ensure proper firewall rules between jump hosts

As a last resort, you can modify the registry to change CAD behavior:

Windows Registry Editor Version 5.00

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

Note: Requires reboot and affects all sessions on the target machine.