The native way, which still works on Windows 10, is to call SystemParametersInfo() with SPI_SETACTIVEWINDOWTRACKING, SPI_SETACTIVEWNDTRKZORDER, and SPI_SETACTIV

The native way, which still works on Windows 10, is to call SystemParametersInfo() with SPI_SETACTIVEWINDOWTRACKING, SPI_SETACTIVEWNDTRKZORDER, and SPI_SETACTIVEWNDTRKTIMEOUT, followed by a broadcast WM_SETTINGCHANGE message. See my MouseWinX tool I linked elsewhere if you want an example.