Formatting a hard drive or installing a new OS over an existing OS will delete the soft-license of your Largo. The license will be useless forever. If you want to restore the license of your PPG Wave 3.V please send an email with the following information to our support: support@waldorfmusic.de * Your 32-digit license activation code of your original version of the PPG Wave 3.V. * Your SeL-license-number (you can find it I the left area of your eLicense Control Software) * A jpg/pdf-scan of the invoice of your PPG Wave 3.V or your order or customer number of the purchase at our online shop. After verifying your information we can then issue a new license to you.