It is not possible to answer that question without more information, and it does not seem to be a question about Moodle.
My son has uploaded a power point be graded by his teacher but she says it is password protected. Are you saying he did not password protect the upload, but that he password protected the power point file on his computer?
Hello there. Yes - it is more than likely he password protected his powerpoint when he saved it, and then when he uploaded it to Moodle his teacher can't view it because it is password protected. He needs to open his powerpoint again and remove the password and then reupload it (if he is allowed to reupload) In 2007 you open it with the password and then go to the Office button (top left) and then prepare and then encrypt document,
... or tell the teacher what his password is ...