It sounds like you may have removed the Informix database server without properly backing up or saving the login information, which is why you are unable to recall the password. Unfortunately, if you did not save or record the password elsewhere, it is likely that you will not be able to retrieve it.

When you re-install the Informix database server, you will need to set a new password. It is recommended to make sure you have a secure way of storing your passwords in the future so that you can easily retrieve them if you forget. Also it's a good practice to change your password periodically.