Cognos Express: Xcelerator Installation Error
Cognos Express: Xcelerator Installation Error (Previous Installation Detected)
This is a pretty common error even though you have correctly uninstalled the software via Control Panel or using the uninstall executable.
The solution is to actually remove and delete the folder:
C:Program Files (x86)Zero G Registry
This folder may be hidden, so in order to see it you will need to Show Hidden Folders and Files under the Folder Options of Windows Explorer. Please ensure you backup the folder beforehand.