This how-to is a description of the solution in this video.
I don't remember clearly but I think I got this TI-Nspire CX CAS calculator as a gift from my library tutoring job. While I was tinkering with it I got it into the Press-To-Test mode. I thought the "test" means some system self-evaluation stuff, but turns out it means an exam at school or something like SAT. The mode heavily restricts the available features on the calculator as required by testing institutions.
To get out of it we need to use TI-Nspire Computer Link. TI provides installers for Windows and macOS.
- Create an empty Note on the calculator, save it as "Exit Test Mode".
- Install TI-Nspire Computer Link on the computer and open it.
- Connect the mini-USB socket on the calculator to a USB socket on the computer.
- Refresh the device list and choose the calculator.
- Drag and drop the "Exit Test Mode" Note file to anywhere on the computer.
- Drag and drop the "Exit Test Mode" Note file from the computer to the "Press-To-Test" folder.
If successful, we should see the "Press-To-Test" folder disappear, and Press-To-Test mode gone.