Files installed in the Windows Vista Program Files folder are opened as read-only files in Microsoft Excel, even though that property is not set. If you want to modify the Crystal Ball Examples files, save them under another name before attempting to run a simulation on them.
If you are using Windows Vista, familiarize yourself with the locations of folders mentioned in this guide, such as My Documents and Application Data. For example, My Documents is under C:\Users instead of C:\Documents and Settings as in earlier versions of Windows.