SystemTaskBar Resize by C++ or C#

Question

I need to change the size of System TaskBar, see the code list belov. The first part works correct, the second works correct too, but nothing happens, where mistake?

//resizing desktop
HWND hManager = FindWindowA("Progman", "Program Manager");
HWND hShell = GetWindow(hManager, GW_CHILD);
BOOL bResult = MoveWindow(hShell, 100, 100, 300, 300, 1);
if (!bResult)
    printf("Error code %d \n", GetLastError());
else
    printf("MoveWindow success \n");  

//resizing desktop tray
HWND hTray = FindWindowA("Shell_TrayWnd", "");
bResult = MoveWindow(hTray, 100, 100, 300, 300, 1);
if (!bResult)
    printf("Error code %d \n", GetLastError());
else
    printf("MoveWindow success \n");