When you open a workbook, Excel may display multiple windows that contain a copy of that same workbook

Symptoms

When you open a workbook, Microsoft Excel may display multiple windows that contain a copy of that same workbook. Additionally, the title bar displays the workbook name followed by a colon and a number, such as Book1:1 and Book1:2. The taskbar in Microsoft Windows also displays a button for each of these windows.

Cause

This behavior occurs if the workbook was saved when multiple windows were open for that workbook.

Resolution

To change this behavior, close the extra windows, and then save the workbook. To do this, follow these steps:

1. Click the Close button (the X in the upper-right corner) of the window that you do not want.
   
   NOTE: If you click Close on the File menu, Excel closes all windows that contain the workbook. Because the settings are retained, you will see all the windows again the next time you open the workbook.

2. Repeat step 1 until only the window that you want is open.
   
   NOTE: When only one window is still open, the title bar no longer displays a colon and a number.

3. Press CTRL+S to save the workbook.

More Information

Excel allows you to open multiple windows to view a single workbook. This is useful when you want to view different sheets in the same workbook or different areas of a large worksheet simultaneously. For example, to view multiple sheets in the active workbook, follow these steps:

1. Press CTRL+N to create a new winodw.
   
   Excel designates multiple windows of the same workbook by appending a colon and a number to the file name on the title bar.

2. Switch to the new window, and then click a sheet that you want to view.

3. Repeat steps 1 and 2 for each sheet that you want to view in a window.

If you close and save the file when you are viewing multiple windows, the window settings are retained. Therefore, when you reopen the workbook, you see the same multiple windows.