PDF files are now seen everywhere in modern life, from online manuals to important work documents. Some of these documents are given security levels, using inbuilt Adobe Acrobat functions, for privacy or to prevent accidental changes. However, these measures can get in the way for users, so it's handy to have the free PDF Unlocker program on hand. This software unlocks PDF owner and user restrictions to make files fully viewable and editable, without damaging metadata. You can unlock files in bulk too, ideal for work documents which need to be changed.