>Ed, please help me...
>I don't know what means the parameters use in functions of RegKey FFC. Which method I need to call and your respective parameters I need to pass to retrieve the value of these regkey "HKLM\HARDWARE\DESCRIPTION\System\CentralProcessor\0\~MHz"?

It is not available to systems running Win9x/WinME at all; on NT/Win2K and WinXP, you'd need to use GetRegKeyValue, with a key specifier of "HARDWARE\DESCRIPTION\System\CentralProcessor\0\~MHz", a Hive Identifier of HKEY_LOCAL_MACHINE (a constant defined in REGISTRY.H) and a KeyValueName of "" (the empty string.) It is not available at all in any case to systems running Win95/Win98 or WinME, and requires different keys under Windows Terminal Server, since there are keys for both the client and the Terminal Server box, and different keys under WinNT/2K/XP in a multiprocessor machine, since the processor affinity for a given process may not be to the first enumerated CPU. Using this key is a poor idea.