SPI_SETMOUSESPEED
Windows NT 5.0 and later, Windows 98: Sets the current mouse speed. The pvParam parameter must point to an integer between 1 (slowest) and 20 (fastest). A value of 10 is the default. This value is typically set using the mouse control panel application.
The SystemParametersInfo function retrieves or sets the value of one of the system-wide parameters. This function can also update the user profile while setting a parameter.