When you install Office Web Apps to your environment, it becomes highly integrated with your SharePoint. You have to be obey some important rules if you want to uninstall one of these coupled components, Office Web Apps and SharePoint.
- After you unistalled Office Web Apps from the Control Panel, you might get an error that Office Web Apps has already been uninstalled.
- If you uninstall SharePoint 2010 before uninstalling Office Web Apps and try to reinstall SharePoint 2010, you will get an error that there is a conflict with SharePoint 2010 on the same server.
To resolve these issues, please read “You cannot use ‘Programs and Features’ in Control Panel to remove Office Web Apps from a Windows Server 2008-based computer“.
It’s much better to deactivate Office Web Apps instead of uninstalling it. You can find detailed information about deactivating Office Web Apps in the article “Deactivate or Uninstall Office Web Apps (installed on SharePoint 2010 Products)“