Error Opening Second Workbook

When you open a second Excel workbook, do you see an error message indicating that "PERSONAL.XLS is already open?" If so, this problem has to do with how you are opening the second workbook.

There are two ways you can open workbooks: either from within Excel or from the operating system. Opening a workbook from within Excel is done by using the Open tool on the toolbar or by choosing File | Open. (In Excel 2007 you click the Office button and then click the Open option.) Opening a workbook from the operating system is done if you double-click on a workbook icon.

Every time you open a workbook from the operating system, you are starting another instance of Excel. The error message appears only if you have a Personal.xls workbook on your system and only if you open a second workbook using the operating system method. The first time you open a workbook, it loads Personal.xls. The second time you open a workbook (remember—you are actually opening another instance of Excel) the program tries to load Personal.xls again. Since it is already open, you get the error.

The solution is to open the second workbook from within Excel, not from the operating system. Use the method of opening a workbook appropriate within your version of Excel and you won't see the error message.

If you must open a second instance of Excel, and you don't want the error message, find the Personal.xls workbook using Windows' Search feature. (Do this in Windows, not in Excel.) Right-click the file and choose Properties. In the Properties dialog box for the file, choose to make the file Read-Only. Once the file is read-only, you no longer get the error when you open up secondary instances of Excel. Why? Because the first instance doesn't leave the file open due to it being read-only.

You can also bypass the error condition completely if you make one small configuration change in Excel. Follow these steps if you are using a version of Excel prior to Excel 2007:

1. Choose Options from the Tools menu. Excel displays the Options dialog box.
2. Make sure the General tab is displayed. (Click here to see a related figure.)
3. Make sure the Ignore Other Applications check box is not selected.
4. Click OK.

If you are using Excel 2007, then you must follow these steps:

1. Click the Office button and then click Excel Options. Excel displays the Excel Options dialog box.
2. Click Advanced at the left side of the dialog box.
3. Scroll through the options until you can see the General group. (Click here to see a related figure.)
4. Make sure the Ignore Other Applications That Use Dynamic Data Exchange (DDE) check box is not selected.
5. Click OK.

According to Excel's help system, if the Ignore Other Applications check box is selected, then Excel won't share DDE information with other applications. This isn't all, however—it also affects how Excel starts when you double-click on a workbook in Windows and you already have Excel open. If the option is cleared (as it should be), then Excel starts the new workbook in the current instance of Excel. If it is selected (as it may be), then Excel tries to open a second instance of itself, and you will see an error message if you have a Personal.xls file on your system.

If changing the Ignore Other Applications check box causes unforeseen problems in other ways you use Excel, then you might also consider converting your Personal.xls file to an add-in. (How to create add-ins has been covered in other issues of ExcelTips.) Add-ins are opened in a special status, akin to read-only, and can therefore be opened by more than one instance of Excel.