NeverOverwrite

Right-click a folder and select 'Monitor Folder'

Decide if subfolders should be monitored and click "Start Monitoring"

Confirmation the folder is being protected

After you have made changes in a file and saved, right-click the file and select "See Previous Versions"

View the list of all points in time the file has been saved. Double-click any version (or click Preview) to open the file as it was then

You can also watch a short video of NeverOverwrite being used with Microsoft Word.