Try this first.
Close Excel first and On the Windows Taskbar
1) Start>Run "excel.exe /unregserver"(no quotes)>OK.
2) Start>Run "excel.exe /regserver"(no quotes)>OK.
See the space between exe and /regserver
You might have to designate a full path to excel.exe.
In that case Start>Run "C:\yourpath\excel.exe" /regserver(quotes
required)>OK
If no joy go with this...........assuming WindowsXP OS
Append a /e to your Excel startup command to prevent Book1 from opening.
Go to Start>Settings>Control Panel>Folder Options>File Types
If using WinXP OS you would scroll down to .XLS then "Advanced">Open>Edit.
In Command line the path should be similar to this....
"C:\PROGRAM FILES\MICROSOFT OFFICE\OFFICExx\EXCEL.EXE" /e
You must have the double quotes and the <space>/e prevents a new blank book
from opening.
Below have "use DDE" checked and this in the DDE message box....[open("%1")]
Application should read "Excel"(no quotes)
Gord Dibben MS Excel MVP