This information is for people who have already purchased a particular product, and would like to take advantage of an upgrade offer to move up to a higher product as listed on the product buy page.
To qualify you must own, within your OtsZone.com profile, a valid and current license for the product you wish to upgrade from. You can see all of your current licenses by going to the "My Licenses" page while logged into your profile.
Copy the PDI code of the product you wish to upgrade, as you'll need this during the ordering process, then simply click on the appropriate upgrade link on the product buy page. During the checkout process you will be required to enter your OtsZone.com profile email address, and the PDI you have previously copied corresponding to the product you are upgrading from.
NOTE: If the license quantity of the license/PDI you are upgrading from is multi-quantity (ie. for use on more than one computer) then you should order the appropriate matching quantity of licenses for the upgrade product. If the two don't match, the process will be somewhat slowed as OtsZone.com staff will have to contact you to find out how you wish to proceed, and this may require having to manually "break-up" your old multi-quantity license.