As with most computer programs you already use on either Windows or the Macintosh, you know that files are generally opened via the File >> Open command. In many programs, the keyboard shortcut used to open files is Ctrl+O.

Acrobat uses the same menu and keyboard shortcuts to access the Open dialog box where you browse your hard drive, open folders, and ultimately select a file to open. When you doubleclick a filename or click the Open button when a file is selected, the file opens in Acrobat. All Acrobat viewers also offer you a tool to open files.

Click the Open tool in the File toolbar and the Open dialog box appears just as if you had used the Open menu command or keyboard shortcut. Any one of these methods opens a PDF document or a document of one of many different file types that can be converted to PDF on-the-fly while you work in Acrobat.

When you launch Acrobat and view and/or edit PDF documents, Acrobat keeps track of the most recently opened files. By default, Acrobat keeps track of the last five files you opened. In the Startup preferences you can change the value to as many as ten recently viewed files.

The files are accessible at the bottom of the File menu (Windows) or the File >> Open Recent File submenu on the Macintosh. You can see five filenames at the bottom of the File menu from Acrobat running under Windows. You have another option for viewing files that were previously opened in an Acrobat session.

The History menu command appearing over the recent file list offers you submenus for viewing files from a history as long as the previous 12 months. Until you clear the History by selecting the Clear History menu command, all the files you viewed over the last 12 months are displayed in a scrollable list.

You can break down the history according to the files viewed Today, Yesterday, the Last 7 Days, the Last 14 Days, and the Last 30 Days, as well as the Last 12 Months. Macintosh users can find the History submenu command appearing at the top of the list of files when you choose File >> Open Recent File.