any ReadReg(int 1, str 2, str? 3, any? 4)
Reads the value of the specified key in the 32-bit or 64-bit system registry. First parameter is the root key, such as HKEY_LOCAL_MACHINE (32-bit) or HKEY_LOCAL_MACHINE_64 (64-bit). Constants for use with this parameter are declared in ISPPBuiltins.iss accompanying ISPP. Second parameter specifies a subkey. Third parameter specifies the name of the value, if this parameter is omitted, a default value is assumed. Last optional parameter may be used to specify the default value that will be returned on failure.
Note that this function can return a value of any type depending on the type of actual value in the registry.