A PDF, or portable document format, file is ideal for storing information in which you want to keep all of your formatting. Unlike many word-processing programs, in which formatting can change when a file is emailed or viewed on another computer, a PDF keeps formatting uniform no matter how it is shared or where it is viewed. The default settings on a PDF also prevent the document from being altered by users other than you, which provides some document security. If you want an even more-secure document, you can also set a password to open the PDF file.
Adobe LiveCycle Designer ES
Launch Adobe LiveCycle Designer ES from the "Start" menu of your computer. Open the PDF that you want to protect with a password by going to "File," "Open," finding the file in the window that comes up and double-clicking the file.
Return to the "File" menu once the file is open on the screen. Choose "Form Properties," switch to the "PDF Security" tab, click on "Require A Password to Open the Document," and click the "OK" button.
Go to the "File" menu again and choose "Save As." In the "Save As" window, pull down the menu by "Save As Type" and select "Adobe PDF Form (*.pdf)." The "Set Document Open Password" box automatically pops up.
Enter the password that you want to set for the PDF file into the box provided. Type the password a second time in the "Confirm" box and then click the "OK" button. The file saves and can only be opened again by entering the password.
Open Adobe Acrobat on your computer. To open Acrobat, go to "Start>All Programs>Adobe>Adobe Acrobat." When Acrobat opens, go to "File>Open" and open the PDF you went to password-protect.
Go to the "File" menu again and choose the "Document Security" feature. When the window comes up, pull down the menu by "Security Options" and choose the "Acrobat Standard Security" option.
Click the "Password required to open document" box to check it and an empty box appears. Type the password that you want to use to open the file into the box. Click the "OK" button to make the change take effect.
Save the file by going to the file menu and clicking "Save." If you want to save the password-protected file as a separate file, while leaving a version of the file without password protection, you can choose "Save As" and enter a name for the new password-protected version of the file. The original file remains the same and can still be opened without a password.
Go to the "Start" menu, "All Programs" and open novaPDF on your computer. Pull down the "File" menu, select "Open" and open the PDF to which you want to add a password.
Open the "File" menu again and select "Print." When the "Print" window comes up, click on novaPDF Pro and then click "Properties" in the "novaPDF Pro" window.
Click the "Security" tab and choose "High Level Encryption." In the window that comes up, enter the password you want to use in the "User Password" box, and click the "OK" button. A new password-protected PDF document is created.