Uninstall the version you have. Go to the official NCH Software website and specifically look for the link that says "Download the free version here" (usually located in a small blurb at the bottom of the page). This version shouldn't require a registration code for basic home use. 2. Restoring a Lost Registration Code
Use the NCH Software Password Recovery page. Enter the email address you used at purchase, and they will email you your key. pixillion image converter free registration code fix
Ensure there are no hidden spaces at the beginning or end of the code when you paste it. 4. Reliable Alternatives Uninstall the version you have