It makes the possibility of an unwanted user to break into your account much smaller.
I'd go with two answers.
A: To permanently remove a file from her computer, Sarah doubled-clicked on the My Computer icon and searched for her file under the “Uninstall or change a program” menu option.
Or
B: Empty the Recycle Bin.
This question is somewhat not clear. Why I went with the answers above is because I really do not know what kind of a file Sarah wants to permanently remove. You can permanently delete a program file installed in the computer by following the procedure in option A. The option above will take you to the control panel and you'll be able to select the program you'd want to permanently remove. If you had initially deleted a file like a picture or a document or anything else that you necessarily do not need, it will go to recycle bin. You can head over there and select the Empty the Recycle Bin option to permanently delete the file.
