windows registry and winapi

I just wrote some Java to JNI to C++ code to get and set values of the windows registry under the root Win32RegKey.HKEY_CURRENT_USER and path "Control Panel\\Mouse". I can change the DoubleClickSpeed, SwapMouseButtons, and MouseSensitivity registry values but they don't take effect on the mouse.
Is there a winapi call that provides this functionality?
Any help would be greatly appreciated. Thanks.

check out SystemParametersInfo() in the MSDN
Some of the constants to notice:
SPI_SETMOUSEBUTTONSWAP
SPI_SETMOUSESPEED
SPI_SETDOUBLECLICKTIME