Every Excel user knows how to open a spreadsheet: Click on File (or the whimsical Office button in Excel 2007), choose the Open command, select a file, and then click the Open button. In this article, I'll explain several hidden techniques that can give you more control over unfamiliar spreadsheets.
Before we get to the specifics on the hidden features, first double-click on the title bar of the Open dialog box in Excel. This expands the window so that you can see more files without scrolling from side-to-side. Simply double-click on it again to restore it to its traditional size. Next, click once on a file, and then click the arrow on the right edge of the Open button, as shown in Figure 1. Most users never realize that a menu exists here, which contains options that may vary based on your version of Excel: