You can open a PDF in many ways: from within the Reader application, from your email application, from your file system, or on a network from within a web browser. The initial view of the PDF depends on how its creator set the document properties. For example, a document may open at a particular page or magnification.
Some PDFs are restricted and open only after you enter a password provided to you by the PDF owner. If a document is encrypted, you may need the permission of its creator to open it. In the case of some restricted or certified documents, you may be prevented from printing a file or copying information to another application. If you have trouble opening a PDF or can’t use certain features, contact its author or owner.
If a document is set to open in Full Screen mode, the toolbar, command bar, menu bar, and window controls are not visible. You can exit Full Screen mode by pressing the Esc key if your preferences are set this way, or by pressing Ctrl+L/Command+L.