?PDF documents are used widely by millions of computer users for storing and transferring of information. These documents can be used to store and transport information in the form of text, images and even sound and video. PDF files are easy to share as they are cross platform, and can be used on any computer and any operating system. The introduction of PDF documents greatly changed the way users handled documents on computer. Remarkable Feature of PDF Documents One of the key features that make PDF files so remarkable is the fact that they can be protected by passwords. This protection helps to prevent other users from altering the file information, and also, in some cases, even restricts the access. To unlock any password protected PDF file, user needs to know the password, which means, only intended recipients can view and alter the contents of the password protected PDF documents. Reasons for Using Passwords on PDF Documents People use passwords on PDF files for many reasons. The major reasons can be - the information is private and intended only for some particular users, or the information is copyrighted. By locking the PDF files, user would be preventing unintended users from accessing/changing PDF file contents or protecting the copyrighted information within the file. Thus, password protection of PDF documents is really helpful in cases when user does not want particular information to be shared by everyone; as the information cannot be decompiled or edited in any way when PDF is password protected. User Himself Forgets the Password - Now what? Password protection can sometimes turn into a punishment if user himself forgets the password to his PDF documents and lose access to the password protected PDF files. In this scenario, the only viable solution is to unlock password protected PDF file Unlock Password Protected PDF File . How to Unlock PDF Files? An outside PDF unlock utility tool for unlocking PDF security is a practical way out. There are software tools available that help users to unlock Adobe PDF files. SysTools PDF Unlocker software is perhaps one of the most efficient tools that can easily and quickly unlock Adobe Acrobat PDF documents and can recover password protected files.