To qualify for Duplicate File Detective 4 upgrade pricing, you must own a license for
a previous version. Note that it can be any previous version
(e.g. 1.x, 2.x, or 3.x).
Please provide your existing Duplicate File Detective license key in order to upgrade. If you currently
have Duplicate File Detective installed, you can find your existing license key within the application
itself (see Help | About). Another option is to locate the license email you were sent (via email)
immediately after you purchased (it will contain your license key).
Enter your Duplicate File Detective license key into the field below and click "Validate Now" to proceed.
IMPORTANT: If you purchased Duplicate File Detective license on or after February 17, 2011,
you qualify for a free upgrade license and should NOT use this form (please contact us via email).