Open 'Control Panel' and remove "Excel Server 2008 Enterprise Edition", "Excel Server Service", "Excel Server WebSite" separately.
1.Removing Excel Server 2008 Enterprise Edition
Click "Change/Remove"
Click "OK":
If the database is nor required, Choose "Yes". Otherwise, choose "No".
Click "Yes":
Restart computer after all the component uninstalled.
2. Removing Excel Server Service
Click "Change/remove":
Choose "Yes":
(3) Removing Excel Server Web
Click "Yes". Installation is finished.
Restart the computer.