Office 2007 Users
Please note that you need to have Admin right to be able to use this fix. Download and run the registry file below. When prompted, click yes. When you see the message window that says the registry was successfully entered, click on OK. Try running Excel again.
If you installed SpreadsheetWeb in a different drive than the C: drive, please open the registry file with a text editor (i.e. Notepad) and edit the drive path on the “Manifest” line.
Office 2010 Users
Press File from the main menu and click ‘Options’ button
Press ‘Add-Ins’ and select ‘COM Add-ins’ from Manage options and press’Go’
If ‘SpreadsheetWEB Addin’ is not enabled, select the checkbox and press OK