guys the problem is solved!i tried downloading new os with google chrome and it worked!
i also learned a lot more about working with it.
now i have a question:how can i perform a hard reset on my cx cas?i want it to be like it was at first!without any of my data and programs.how can i do it?

thanks a lot 

guys i have a stupid problem.i cant upgrade the os of the nspire cx cas.i downloaded it from ti website.its a tcc file.how can i upgrade it?please help me its killing me

thanks everybody.i love this site!everybody are so helpful.i hope someday i can help someone else in this forum.
please tell me how can i install programs this programs?i found a guide for installing ndless.but i dont know what should i do about other ones!
is installing ndless needing programs different from installing regulare ones?
i downloaded some programs. they have tow files! one is a .LUA file and the other is .TNS file.
which one i have to install on my cx cas?
thanks again

hello everybody....
i just bought a ti-nspire cx cas calculator.im totally confused!
i dont know what programs should i install.please give me some good programs.and i like to play games on it too!
and please help me with ndless!i dont know what it does.should i install it?

please give me some good and useful programs to install.and some games too.
and please tell me how can i install programs on it?
i have a strange Obsession with electronic stuff like calculator.i dont want anything to go wrong.please help me.thank you!