Look in your %oracle_home%\nlm directory. There should be an exp.nlm,
exp80.nlm, or a exp81.nlm, depending on your Oracle version. After you
find out this, you can use something similar to the following command:
exp system/manager full=y file=volume:dir\expdat.dmp
log=volume:dir\oraexp.log
This command does a whole database export and creates a log in file
oraexp.log.
Saul Rodriguez