HP CIT :SAP Jco is not installed;noclassdeffounderror com\sap\mw\jco\Jco

I'm getting an error..on starting the Change Impact server
SAP Jco is not installed;noclassdeffounderror com\sap\mw\jco\Jco "
what could be the reason behind it.

steps i did before running the Change Impact server,

1.Unzip the sapjco 3 version and copy to a C:\ drive
2.set the classpath=C:\Sapjco\Sapjco.jar
and path = C:\Sapjco
as mentioned in the installation document.
3.Execute the command java -jar c:\sapjco\sapjco3.jar to check the installation is success.(No exceptions !)
4.copy the Sapjco3.jar into the "CIA" directory of mercury folder and copy the sapjco.dll into the c:\windows\system32 file.
5.execute the change impact server..gives out the error,
SAP Jco is not installed;noclassdeffounderror com\sap\mw\jco\Jco "
what coiuld be wrong ?