help for jpcap

i have installed jpcap. it added a file jpcap.dll in my system32 folder.
But when i write any program in java using jpcap an error occurs
that unable to find symbol for each instance of class used.
i googled it but not useful.
So please help me & tell me how to run program.
thank u

Make sure you installed it correctly.

Java does not access the .dll directly. Make sure jpcap.jar is in your classpath.