DiskSorter licenses and discounted license packs may be purchased on the following page:

http://www.disksorter.com/purchase.html

After finishing the purchase process, wait for the following two e-mail messages: the first one with a receipt for your payment and the second one with an unlock key. If you will not receive your unlock key within 24 hours, please check your spam box for e-mail messages originating from support@flexense.com and if it is nor here contact our support team:

After you will receive your unlock key, start the DiskSorter GUI application and press the 'Register' button located in the top-right corner of the window.

On the register dialog, enter your name and the received unlock key and press the 'Register' button to finish the registration procedure.