You will want to verify that you are inputting the correct order number and email address that was used to place the order. Additionally, a reinstall that is initiated too soon after a purchase may result in the order not being recognized by the servers. The system needs approximately 15 minutes to update the database in some situations.
The order may also not be recognized by the system if you are trying to reinstall with an application that is a different version from the one used during the original purchase. For example, if you are trying to reinstall with a version 4 of a product, but you originally purchased with version 3, the eSeller ID is different and thus the system will not recognize your order. You will need to attempt the reinstall using the same application and version that was used originally. If that version is no longer available on the developer's site, you may need to contact the developer's support department directly. Their contact information is on your receipt, or you can retrieve that information by using our After-Purchase Services page: http://store.esellerate.net/support