All warnings from Part 1 still apply.

WARNING: The latest OS will disable the ability to run most games and some programs! Once you update you cannot downgrade! OS 5.4.0 is the last safe OS to update to. Anything higher will require the arTIfiCE jailbreak to run many programs.

If you know what OS your calculator was using, then you can go ahead and search for it on TI-Planet. Otherwise, attempt to install OS 5.4.0 first. If it fails, then you should install the latest OS from TI's website.

Download and install OS 5.4.0: TI-84 Plus CE | TI-83 Premium CE.

If OS 5.4.0 is not supported, then download the latest OS: TI-84 Plus CE | TI-83 Premium CE

In TI Connect CE, click on 'Actions', then 'send OS/Bundle to calculators...'

Navigate to where you saved the OS and select it. It will take a second for TI-Connect CE to load. Once the popup appears, click 'send'.

This will take a few minutes to install.