Hiding the Taskbar and Startmenu (start orb) in Windows Vista

• Download source (VS2008 solution) and demo - 15.5 KB

Introduction

I recently needed to hide the Windows taskbar and startmenu. All the code that I found on the net for this purpose did not work on Windows Vista, so I decided to write some myself.

Background

Hiding the taskbar is very easy, because its window handle can easily been found with a call to the FindWindow WINAPI function:

[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr FindWindowEx(IntPtr parentHandle, IntPtr childAfter,
    string className,  string windowTitle);

IntPtr taskBarWnd = FindWindow("Shell_TrayWnd", null);

Once we know the window handle, we can hide the window using the WINAPI function ShowWindow. If you do this, the taskbar is hidden, but the "Start" button still remains visible. Under Windows XP (and before) this was also easy, because the "Start" button was a child window of the taskbar and its window handle can be found with a call to FindWindowEx:

IntPtr startWnd = FindWindowEx(taskBarWnd, IntPtr.Zero, "Button", "Start");

However, this changed with Windows Vista: If you look closely you will see that the Vista start orb is overlapping the taskbar a little bit. The start orb is not a child window of the taskbar anymore, but a window of its own. To find the handle of this window I proceed as follows:

First I get the id of the process that owns the taskbar window:

[DllImport("user32.dll")]
static extern uint GetWindowThreadProcessId(IntPtr hwnd, out int lpdwProcessId);

int procId;
GetWindowThreadProcessId(taskBarWnd, out procId);

Then I enumerate all threads of this process by using managed code. For each thread I enumerate its windows by using the WINAPI function EnumThreadWindows:

Process p = Process.GetProcessById(procId);
if (p != null)
{
    // enumerate all threads of that process...
    foreach (ProcessThread t in p.Threads)
    {
        EnumThreadWindows(t.Id, MyEnumThreadWindowsProc, IntPtr.Zero);
    }
}

For the EnumThreadWindows function allows Windows to call my callback function MyEnumThreadWindowsProc for each window of the given thread. Within the callback function I check whether the caption of each window is "Start" (which is true only for the start menu window):

private static bool MyEnumThreadWindowsProc(IntPtr hWnd, IntPtr lParam)
{
    StringBuilder buffer = new StringBuilder(256);
    if (GetWindowText(hWnd, buffer, buffer.Capacity) > 0)
    {
        if (buffer.ToString() == VistaStartMenuCaption)
        {
            vistaStartMenuWnd = hWnd;
            return false;
        }
    }
    return true;
}

Using the Code

I packed everything in a single static class so you don't have to worry about WINAPI. Just include the class Taskbar in your application and call the static method Hide or Show. That's all, really! Of course this works on both Windows XP and Vista.

// hide the taskbar and startmenu
Taskbar.Hide();

History

2008-04-23: Version 1.0 posted.
2008-07-16: Version 1.1 posted, sources updated so they should work also on non-english versions of Vista.