rshivagami, only to add : absolutely is NOT required an external tool like that, exp is a coomand-line tool, in the DOS prompt you could do :

SET ORACLE_HOME=pathtothedesiredhome
SET PATH=%ORACLE_HOME%\BIN;%PATH%
SET ORACLE_SID=desiredSID

after this the correct exp.exe would be used...

Regards,

Chiappa