
If this issue occurs when you double-click a document from Microsoft Windows Explorer and the document should be associated with an Office program whose installation state is Installed on First Use, follow these steps: Method 2: Demand Install the Office Program In this example, computer is the computer name, yyyymmdd is the date that the RegClean utility made the registry changes, and hhmmss is the time that the RegClean utility made the registry changes. The RegClean utility creates a file in the following format: This restores the registry entries that were removed.

To undo changes made by the RegClean utility, locate the Undo.reg file, and then double-click the Undo.reg file. Method 1: Undo the Registry Changes from RegClean To resolve this issue, try the following methods in the order that they appear in. This issue occurs for any Microsoft Windows Installer product on which the program's installation state is set to Installed on First Use. This issue occurs because the RegClean utility is not compatible with the products listed in the "Applies to" section. Instead, the Open With dialog box appears and the Office program is not listed. When you install a Microsoft Office program whose installation state is Installed on First Use and then double-click a document that is associated with that program, the Office program may not start. The RegClean utility finds errors in the System Registry, and you receive the option to Fix Errors in the RegClean utility.

When you run the RegClean utility after you install one of the products listed in the "Applies to" section, you may experience one of the following symptoms:
