public static uint LaunchProcessAsUser(string cmdLine, IntPtr token, IntPtr envBlock)
        {
            bool result = false;

            PROCESS_INFORMATION pi = new PROCESS_INFORMATION();
            SECURITY_ATTRIBUTES saProcess = new SECURITY_ATTRIBUTES();
            SECURITY_ATTRIBUTES saThread = new SECURITY_ATTRIBUTES();
            saProcess.nLength = (uint)Marshal.SizeOf(saProcess);
            saThread.nLength = (uint)Marshal.SizeOf(saThread);

            STARTUPINFO si = new STARTUPINFO();
            si.cb = (uint)Marshal.SizeOf(si);

            si.lpDesktop = @"WinSta0\Default"; //Modify as needed
            si.dwFlags = ProcessAsUser.STARTF_USESHOWWINDOW | ProcessAsUser.STARTF_FORCEONFEEDBACK;
            si.wShowWindow = ProcessAsUser.SW_SHOW;
            //Set other si properties as required.

            result = ProcessAsUser.CreateProcessAsUser(
                token,
                null,
                cmdLine,
                ref saProcess,
                ref saThread,
                false,
                ProcessAsUser.CREATE_UNICODE_ENVIRONMENT,
                envBlock,
                null,
                ref si,
                out pi);

            if (result == false)
            {
                int error = Marshal.GetLastWin32Error();
                string message = String.Format("CreateProcessAsUser Error: {0}", error);
                Debug.WriteLine(message);

            }

            return result ? pi.dwProcessId : uint.MaxValue;
        }
 public static extern bool CreateProcessAsUser(
     IntPtr hToken,
     string lpApplicationName,
     string lpCommandLine,
     ref SECURITY_ATTRIBUTES lpProcessAttributes,
     ref SECURITY_ATTRIBUTES lpThreadAttributes,
     bool bInheritHandles,
     uint dwCreationFlags,
     IntPtr lpEnvironment,
     string lpCurrentDirectory,
     ref STARTUPINFO lpStartupInfo,
     out PROCESS_INFORMATION lpProcessInformation);
 private static extern bool DuplicateTokenEx(
     IntPtr hExistingToken,
     uint dwDesiredAccess,
     ref SECURITY_ATTRIBUTES lpThreadAttributes,
     Int32 ImpersonationLevel,
     Int32 dwTokenType,
     ref IntPtr phNewToken);
        public static uint LaunchProcessAsUserPid(string cmdLine, IntPtr token, IntPtr envBlock)
        {
            bool result = false;

            PROCESS_INFORMATION pi = new PROCESS_INFORMATION();
            SECURITY_ATTRIBUTES saProcess = new SECURITY_ATTRIBUTES();
            SECURITY_ATTRIBUTES saThread = new SECURITY_ATTRIBUTES();
            saProcess.nLength = (uint)Marshal.SizeOf(saProcess);
            saThread.nLength = (uint)Marshal.SizeOf(saThread);

            STARTUPINFO si = new STARTUPINFO();
            si.cb = (uint)Marshal.SizeOf(si);

            //if this member is NULL, the new process inherits the desktop
            //and window station of its parent process. If this member is
            //an empty string, the process does not inherit the desktop and
            //window station of its parent process; instead, the system
            //determines if a new desktop and window station need to be created.
            //If the impersonated user already has a desktop, the system uses the
            //existing desktop.

            si.lpDesktop = @"WinSta0\Default"; //Modify as needed
            si.dwFlags = STARTF_USESHOWWINDOW | STARTF_FORCEONFEEDBACK;
            si.wShowWindow = SW_SHOW;
            //Set other si properties as required.

            result = CreateProcessAsUser(
                token,
                null,
                cmdLine,
                ref saProcess,
                ref saThread,
                false,
                CREATE_UNICODE_ENVIRONMENT,
                envBlock,
                null,
                ref si,
                out pi);

            if (result == false)
            {
                int error = Marshal.GetLastWin32Error();
                string message = String.Format("CreateProcessAsUser Error: {0}", error);
                Debug.WriteLine(message);

            }

            return result ? pi.dwProcessId : uint.MaxValue;
        }
        public static IntPtr GetPrimaryToken(int processId)
        {
            IntPtr token = IntPtr.Zero;
            IntPtr primaryToken = IntPtr.Zero;
            bool retVal = false;
            Process p = null;

            try
            {
                p = Process.GetProcessById(processId);
            }

            catch (ArgumentException)
            {

                string details = String.Format("ProcessID {0} Not Available", processId);
                Debug.WriteLine(details);
                throw;
            }

            //Gets impersonation token
            retVal = OpenProcessToken(p.Handle, TOKEN_DUPLICATE, ref token);
            if (retVal == true)
            {

                SECURITY_ATTRIBUTES sa = new SECURITY_ATTRIBUTES();
                sa.nLength = (uint)Marshal.SizeOf(sa);

                //Convert the impersonation token into Primary token
                retVal = DuplicateTokenEx(
                    token,
                    TOKEN_ASSIGN_PRIMARY | TOKEN_DUPLICATE | TOKEN_QUERY,
                    ref sa,
                    (int)SECURITY_IMPERSONATION_LEVEL.SecurityIdentification,
                    (int)TOKEN_TYPE.TokenPrimary,
                    ref primaryToken);

                //Close the Token that was previously opened.
                CloseHandle(token);
                if (retVal == false)
                {
                    string message = String.Format("DuplicateTokenEx Error: {0}", Marshal.GetLastWin32Error());
                    Debug.WriteLine(message);
                }

            }

            else
            {

                string message = String.Format("OpenProcessToken Error: {0}", Marshal.GetLastWin32Error());
                Debug.WriteLine(message);

            }

            //We'll Close this token after it is used.
            return primaryToken;
        }