You receive a "This application requires the Windows installer to run" error message when you start an Office program from a network location

When you double-click a file such as Excel.exe from a network administrative installation source for Office XP, you receive the following error message: If you click Cancel, nothing happens. If you click OK, you receive the following error message: The Windows Installer service is installed after you receive the first error message, so if you double-click a file such as Excel.exe again, you only receive the second error message.

This error message occurs because the Office program was not installed by running Setup. For example, if you receive the error message in the "Symptoms" section of this article when you double-click a shortcut, it may be that the shortcut was installed by an edition of Office that is no longer installed on your computer. To test this possibility, double-click the program file (for example, Excel.exe), and determine whether you continue to receive the error message.

To work around this problem, double-click the Setup.exe file in the root of the installation source to install Office.

NOTE: The Office program files for Office XP are now contained inside a cabinet file on the CD-ROM.