You have the option of setting a password for the file by clicking on Set Password in the setup area. You should know that Excel files protected by passwords are relatively easy to 'crack', so setting one not deter people who are determined to access the file. That said, it is a relatively easy security solution to implement.
While we are on the subject, a few more words about the types of information you are storing and securing it are in order. First, I would recommend keeping notes on your interactions with students only to the extent that they serve as a ‘memory aid’ for you. Try to keep the notes as brief and cryptic as possible while still being meaningful to you.
Another method of securing the file would be to keep it on a removable disk (like a 'Flash' or 'Thumb' drive) so you could keep it with you when you are not at your computer. A potential problem with this method, though, is that the relatively small removable disk drives are easy to misplace. If you have a locking file cabinet or drawer in your office, you could keep the removable disk drive in the locked drawer when it is not in use - addressing the issue of accidentally misplacing it while retaining the security benefits of not having the file on your computer.
A 'feature' of the TimeTracker is also a potential security
drawback. When you open the TimeTracker file, a backup copy
is created and kept in the location specified at the bottom
of the Main user interface.
While this backup file is in a location most people would not
routinely look in, the file does exist there.