Putting a password on a PDF file means securing a PDF file from copying, printing, and editing without your permission. Many people do not know how to put a password on a PDF file. Users faced hindrances while putting a password on a PDF file. Today, I suggest you use the OSTtoPSTAPP PDF Protector Program, which helps you easily put a password on a PDF document. With the help of this application, you can secure your PDF files by locking them with a special password. This utility is suitable for all users. You can set the password of your PDF file according to your choice. This program also has the feature of Bulk locking of PDF files. You can easily download this app on all Windows operating systems.