Hi all.
I thought my Nspire (classic clickpad) was dead about two years ago, as I could never get it to turn on, even with fresh batteries. But yesterday I put some new ones in to test it and somehow it actually turned on! So I was going through and all my files were still there, Ndless, GB/C games, etc. But I couldn't open any of my documents except for the one already open. I quickly realized this was because I was running OS 1.1 (I think for Ndless compatibility, this was a few years ago that I last used it), and it didn't even have any of the built-in programming functionality (what a pita!).

So I decided I'd upgrade and see what's out there, and I came across OS 3 and Ndless 3.1. So, I'm planning on upgrading to those (if that's recommended right now?). I downloaded the latest Ndless 3.1 beta, Nspire OS 3.1.0.392, TNOC 1.24, and the Nspire Student Software. Just to be clear (don't want to mess anything up), I run TNOC on the OS 3.1 file and it removes Boot2, which ensures I can still downgrade, then I use the Student Software to send the TNOC'd OS 3.1 to my Nspire, install it, then I put on Ndless 3.1 and install that, and I'm good to go? Thanks all for any help, love Omnimaga, and I'm glad I can get back into calc programming.

edit: Alright, well I tried using TNOC to take out the boot2 and the samples, and just the boot2, and both files can't be installed to the calc for being an "invalid or corrupt OS". Is this because I'm trying to update from 1.1?

edit again: Tried updating to 1.7 this time, no TNOC, it's saying the same thing for that. Not sure what to do now?

You did it right, because the 1.1 -> 3.1 upgrade procedure is to:
* unless the About screen shows that you already have boot2 1.4.1571, install OS 1.7 without having suppressed the boot2 with TNOC, so that the boot2 is upgraded to 1.4.1571;
* install a TNOC'ed OS 3.1.

It's odd that the calculator is refusing the upgrades... it usually does that only when there's a CAS / non-CAS mismatch, but I hesitate to say that this is what you did

Make sure to uninstall Ndless before upgrading. Early versions had a bug blocking OS upgrade. You have to reboot the calculator while pressing theta if I remember well.
Then follow Lionel's recommendations.