You may be looking in the wrong place. On Windows, the init.ora file is in the {Oracle_home}\database directory. Typically the init.ora file points to an ifile stored in {Oracle_home}\admin\{sid}\pfile. It's this ifile that contains the startup parameters.
Jee is right that Oracle 9i allows startup to be based on spfiles rather than pfiles. However, this is not mandatory. You should check to see if you are using one by checking the value of the initialization paramter "spfile".