Error code S28 indicates that the license number has no activations remaining. If you need to move a license from one machine to another, please contact us for assistance using our contact form.

Before you contact us, please have your 31-character license number (Single Licenses) or 20-character claim number (Volume, Concurrent, or School-Managed Licenses) accessible. This license number can be found on:

• Your software's CD Sleeve
• Your software's confirmation e-mail
• The "About" dialog in TI-Nspire Family software version 3.0 and above.

If this article is not helpful, please contact us here.