See http://www.pinvoke.net/default.aspx/kernel32/OpenProcess.html for the OpenProcess API.

    private static extern IntPtr OpenProcess(

        hProcess = StatusBar.OpenProcess(ProcessAccessTypes.PROCESS_ALL_ACCESS, false, this.OwningPID);

    IntPtr process = OpenProcess(ProcessAccessFlags.VMOperation | ProcessAccessFlags.VMRead |

    static extern IntPtr OpenProcess(ProcessAccessFlags dwDesiredAccess, [MarshalAs(UnmanagedType.Bool)] bool bInheritHandle, uint dwProcessId);

    internal static extern bool OpenProcessToken(IntPtr h, int acc, ref IntPtr

        retVal = OpenProcessToken(hproc, TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, ref htok);

          if (NativeMethods.OpenProcessToken(currentProcess, NativeMethods.TOKEN_ADJUST_PRIVILEGES | NativeMethods.TOKEN_QUERY, out tokenHandle))

                                 "OpenProcessToken failed. CurrentProcess: {0}",

      internal static extern bool OpenProcessToken(IntPtr processHandle,

    Private Function OpenProcessToken( _

        If Not OpenProcessToken(hProc, TOKEN_ADJUST_PRIVILEGES Or TOKEN_QUERY, hToken) Then

             "OpenProcessToken failed with error " & lastWin32Error.ToString & ".")

static extern bool OpenProcessToken(IntPtr ProcessHandle,

Private Function OpenProcessToken( _

Declare Function OpenProcessToken Lib "advapi32.dll" ( _

    Source: Link to ''http://groups.google.com/group/microsoft.public.dotnet.general/browse_thread/thread/5742d50ec2e9f798/c702b8d7771f9016lnk=st&q=OpenProcessToken+0x00020000&rnum=1&hl=en#c702b8d7771f9016''

    public static extern bool OpenProcessToken(IntPtr ProcessHandle, UInt32 DesiredAccess, out IntPtr TokenHandle);

        if (!OpenProcessToken(processHandle, TOKEN_READ, out tokenHandle))

    public const int CO_E_FAILEDTOOPENPROCESSTOKEN = unchecked((int)0x8001013C);

    Public Const CO_E_FAILEDTOOPENPROCESSTOKEN As Integer = CInt(&H8001013cUI)

    /// Required to retrieve certain information about a process, such as its token, exit code, and priority class (see OpenProcessToken).

Used with OpenProcess.

        static extern bool OpenProcessToken(

            if (OpenProcessToken(pId, TOKEN_QUERY, out hToken)) {

        public const int CO_E_FAILEDTOOPENPROCESSTOKEN = (int)(0x8001013C - 0x100000000);

   internal static extern IntPtr OpenProcess(int dwDesiredAccess, bool bInheritHandle, int dwProcessId);

        IntPtr ptrProcess = OpenProcess(QueryLimitedInformation, false, iPID);

public static extern IntPtr OpenProcess(

public static IntPtr OpenProcess(Process proc, ProcessAccessFlags flags)

     return OpenProcess(flags, false, proc.Id);

Declare Function OpenProcess Lib "kernel32" (ByVal dwDesiredAccess As ProcessAccessFlags, bInheritHandle As Boolean, processId As UInt32) As IntPtr

IntPtr handle = OpenProcess(ProcessAccess.QueryLimitedInformation, false, process.Id);

in Token for the user, which is returned by the LogonUser, CreateRestrictedToken, DuplicateToken, OpenProcessToken, or OpenThreadToken function. The token must have TOKEN_QUERY and TOKEN_IMPERSONATE and TOKEN_DUPLICATE access. For more information, see Access Rights for Access-Token Objects.

IntPtr pic = OpenProcess(NativeMethods.ProcessAccessFlags.All, true, (int)pid);

See also PROCESS_BASIC_INFORMATION, PROCESSINFOCLASS, OpenProcess, CloseHandle.

        IntPtr hProc = OpenProcess(0x001F0FFF, false, Process.GetCurrentProcess().Id);

        IntPtr hProc = OpenProcess((ProcessAccessFlags)0x001F0FFF, false, Process.GetCurrentProcess().Id);