Although Microsoft does not recommend it, it is possible to install and use more than one version of Microsoft Excel on the same computer. For example, you can install and use both Microsoft Excel 2000 and Microsoft Excel 97 on the same computer.

This article describes the problems you may encounter when you do this and offers advice about preventing different versions of Excel from conflicting with each other.

Order of Installation

If you want to install and use more than one version of Excel on the same computer, you must install the versions of Excel in ascending order.

For example, if you want to use both Excel 7.0 and Excel 2000 on the same computer, you must install Excel 7.0 first, and then Excel 2000. This is necessary because of the way registry keys, shared programs, file extensions and other settings are managed for each version of Excel.

The following table shows the order in which you should install the versions of Excel:

   Excel       Install
   version     order
   -------     -------

   5.0         first
   7.0         second
   97          third
   2000        fourth
				

The rest of this article assumes that you installed the versions of Excel in this correct order.

Running Multiple Versions of Microsoft Excel Simultaneously

Although it is possible to run more than one version of Excel simultaneously on the same computer, Microsoft strongly recommends that you avoid doing this. For example, if you want to start Excel 97, first quit all other versions of Microsoft Excel that may be running.

Double-Clicking Files in the Windows Explorer

When you double-click a Microsoft Excel workbook (.xls) file, chart (.xlc) file, or add-in (.xla) file in Windows Explorer, the following rules apply:

•	If a version of the program that created the file is running, the file is opened in that version of the program.
•	With Excel 7.0 or 97, if no version of the program that created the file is running, the file is opened in the version of the program that you most recently installed. However, with Excel 5.0, every time you start the program, it registers itself as the last version installed, and will attempt to load the file.

To reassociate files with the programs in a particular version of Excel, run Microsoft Office Setup and click Repair Office. Doing this registers the file associations for the version of Microsoft Office.

See the "Reassociating Microsoft Excel Files" section for more information about this behavior.

If you double-click a file that is not supported by the version of Excel that is already running or that automatically starts, you receive the following error message: If you receive this error message, start the later version of Excel. Then, open the file by double-clicking it in Windows Explorer or by using the Open dialog box (click Open on the File menu).

Reassociating Microsoft Excel Files

When you start Excel 5.0, Microsoft Excel files (.xls, .xlc, and .xla files) are automatically associated with it.

When you start them, Excel 7.0, Excel 97, and Excel 2000 are not automatically associated with Microsoft Excel files; they perform this task only when you install these programs.

Because of this difference in behavior, if you start Excel 5.0, an Excel file that you double-click is always opened in Excel 5.0, unless another version of Excel is already running.

If you want to double-click a file and open it in a newer version of Excel, you can associate Excel files with Microsoft Excel 7.0, 97, or 2000 by using either of the following methods.

Method 1: Reregister Excel Using Setup

In Microsoft Excel 2000, run Setup and click Repair Office.

In Excel 7.0 or 97, run Setup using the /y switch. Using /y instructs the Setup program to register all of the registry keys that are used by Microsoft Excel and to associate Microsoft Excel files with the version of Microsoft Excel that you are installing.

Method 2: Reregister the File Types

To associate Microsoft Excel files with Microsoft Excel 7.0, 97 or 2000, follow these steps:

1.	Double-click My Computer.
2.	On the View menu, click Folder Options. (In Microsoft Windows 2000 or Microsoft Windows XP, click Folder Options on the Tools menu.) Then, click the File Types tab.
3.	In the list of registered file types, scroll down and click Microsoft Excel Worksheet. Then, click Edit.
4.	In the list of Actions, click Open. Then, click Edit.
5.	In the Application used to perform action box, change the path to the Microsoft Excel program file (Excel.exe) so that it refers to the Excel.exe file for Microsoft Excel 7.0, Microsoft Excel 97 or Microsoft Excel 2000. If you are unsure of the location for Excel.exe, click Browse to search for the file.
6.	Click OK. Then, click Close, and then click Close again to close the Options dialog box.

NOTE: If you use one of these methods and you start Microsoft Excel 5.0, Microsoft Excel files are automatically reassociated with Microsoft Excel 5.0. There is no way to prevent this behavior from occurring. If you want to ensure that a Microsoft Excel file is opened in a specific version of Microsoft Excel, start that version of Microsoft Excel before you open the file, or use the Open dialog box to open files.

Inserting Microsoft Excel Objects into Other Programs

If you install multiple versions of Microsoft Excel on a single computer and you insert a Microsoft Excel Worksheet object into another program (for example, Microsoft Word), the most recently installed version of Microsoft Excel is used when you insert the worksheet object.

For example, if you install the following programs on your computer

   Microsoft Word for Windows, version 6.0
   Microsoft Excel for Windows 95 , version 7.0
   Microsoft Excel 2000
				

and then insert a Microsoft Excel Worksheet object into Microsoft Word, a Microsoft Excel 2000 worksheet is added.

Using Automation to Control Microsoft Excel

If you install multiple versions of Microsoft Excel on a computer, you may experience difficulty when you attempt to use Automation to control a specific version of Microsoft Excel.

For example, if you run the following Visual Basic for Applications subroutine in Microsoft Word 97

   Sub AutomationTest()
       Dim xlApp As Object
       Set xlApp = CreateObject("Excel.Application")
       MsgBox xlApp.Version
       xlApp.Quit
       Set xlApp = Nothing
   End Sub
				

the subroutine always creates an Automation session in the version of Microsoft Excel that you most recently installed. So, if you install both Microsoft Excel 97 and Microsoft Excel 2000 on the same computer, the message box in the example displays 9.0, the version number of Microsoft Excel 2000.

NOTE: You cannot separately control Automation of Excel 97 and Excel 2000 when both are installed. Although Excel 97 and Excel 2000 each have their own application class, both have the same CLSID (class id). The last version that you install will contain the path to the Automation server.

   Version of
   Microsoft Excel   Class name
   -------------------------------------

   2000              Excel.Application.9
   97                Excel.Application.8
   7.0               Excel.Application.5
   5.0               Excel.Application.5
				

NOTE: Because Microsoft Excel 5.0 and 7.0 both use the same class name, when both are installed on the same computer, Excel.Application.5 always applies to Microsoft Excel 7.0. There is no way to prevent this behavior. However, Microsoft Excel 5.0 and 7.0 both use the same file format and offer very similar features so you should be able to use Microsoft Excel 7.0 instead of Microsoft Excel 5.0 without side effects.

Shared Programs

You should not experience any problems when you use shared programs, such as Microsoft Equation Editor and Clip Gallery, with any version of Microsoft Excel. Note that the Object dialog box may display more than one entry for each shared program; this behavior occurs because there may be multiple versions of the shared program on the computer.