Backing Up and Restoring Ratings and Tags
All of your data (ratings, tags, settings, etc) is stored in one database file: KeyboardImageViewer.sqlite. Press Windows+R to open a Run dialog and enter
%localappdata%\Keyboard Image Viewer
to go to the folder it is stored in.
Copy this file to back it up and move the file here to restore your settings.
If you've moved or renamed your image folder, or its drive has changed letters, it still might display a blank screen and 0/0 after you restore the KeyboardImageViewer.sqlite file. To tell Keyboard Image Viewer the new location of your files, open up Settings
(F4), go to the Library Folders tab and click "Specify New Location".
After selecting the new folder, all of your ratings and tags should be restored.