C# Signature:

[DllImport("user32.dll", SetLastError=true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int x, int y, int cx, int cy, uint uFlags);

Check the SWP definition on Enums.

VB.Net Signature:

<DllImport("user32.dll", SetLastError:=True)> _
Private Shared Function SetWindowPos(ByVal hWnd As IntPtr, _
     ByVal hWndInsertAfter As IntPtr, _
     ByVal X As Integer, _
     ByVal Y As Integer, _
     ByVal cx As Integer, _
     ByVal cy As Integer, _
     ByVal uFlags As UInteger) As Boolean
End Function

User-Defined Types:

C# Signature:

    public const int SWP_ASYNCWINDOWPOS = 0x4000;
    public const int SWP_DEFERERASE = 0x2000;
    public const int SWP_DRAWFRAME = 0x0020;
    public const int SWP_FRAMECHANGED = 0x0020;
    public const int SWP_HIDEWINDOW = 0x0080;
    public const int SWP_NOACTIVATE = 0x0010;
    public const int SWP_NOCOPYBITS = 0x0100;
    public const int SWP_NOMOVE = 0x0002;
    public const int SWP_NOOWNERZORDER = 0x0200;
    public const int SWP_NOREDRAW = 0x0008;
    public const int SWP_NOREPOSITION = 0x0200;
    public const int SWP_NOSENDCHANGING = 0x0400;
    public const int SWP_NOSIZE = 0x0001;
    public const int SWP_NOZORDER = 0x0004;
    public const int SWP_SHOWWINDOW = 0x0040;

    public const int HWND_TOP = 0;
    public const int HWND_BOTTOM = 1;
    public const int HWND_TOPMOST = -1;
    public const int HWND_NOTOPMOST = -2;

VB.Net Signature:

    Public Const SWP_NOSIZE As Integer = &H1
    Public Const SWP_NOMOVE As Integer = &H2
    Public Const SWP_NOZORDER As Integer = &H4
    Public Const SWP_NOREDRAW As Integer = &H8
    Public Const SWP_NOACTIVATE As Integer = &H10
    Public Const SWP_DRAWFRAME As Integer = &H20
    Public Const SWP_FRAMECHANGED As Integer = &H20
    Public Const SWP_SHOWWINDOW As Integer = &H40
    Public Const SWP_HIDEWINDOW As Integer = &H80
    Public Const SWP_NOCOPYBITS As Integer = &H100
    Public Const SWP_NOOWNERZORDER As Integer = &H200
    Public Const SWP_NOREPOSITION As Integer = &H200
    Public Const SWP_NOSENDCHANGING As Integer = &H400
    Public Const SWP_DEFERERASE As Integer = &H2000
    Public Const SWP_ASYNCWINDOWPOS As Integer = &H4000

Alternative Managed API:

Do you know one? Please contribute it!

Notes:

None.

Tips & Tricks:

Use this to hide the start menu and start bar.

Sample Code:

    public void HideStartBar()
    {
        IntPtr handle;

        try
        {
        // Find the handle to the Start Bar
        handle = FindWindowW("HHTaskBar", null);

        // If the handle is found then hide the start bar
        if (handle != IntPtr.Zero)
        {
            // Hide the start bar
            SetWindowPos(handle, 0, 0, 0, 0, 0, SWP_HIDEWINDOW);
        }
        }
        catch
        {
        MessageBox.Show("Could not hide Start Bar.");
        }
    }

    public void ShowStartBar()
    {
        IntPtr handle;

        try
        {
        // Find the handle to the Start Bar
        handle = FindWindowW("HHTaskBar", null);

        // If the handle is found then show the start bar
        if (handle != IntPtr.Zero)
        {
            // Show the start bar
            SetWindowPos(handle, 0, 0, 0, 240, 26, SWP_SHOWWINDOW);
        }
        }
        catch
        {
        MessageBox.Show("Could not show Start Bar.");
        }
    }