@burro_ciao TI Connect is pretty hit or miss for connectivity. (and mostly miss) You should use TI Connect CE which actually works most of the time. If TI Connect CE can't find your calc, archive everything you care about and then reset your ram. That usually fixes connectivity problems.

@burro_ciao
Alright, I double checked TI Connect CE's supported calcs and it doesn't support the TI-83. So that's unfortunate. I guess you are stuck using TI Connect. You will need to reset your calc's ram before and after doing pretty much anything when dealing with TI Connect. I haven't actually dealt with connecting an 83 to a PC as I just work with 84s. Try resetting your ram, plugging it back in and if that doesn't work, try a couple more times. Sometimes it just doesn't feel like working. Restarting TI Connect or even you PC might help too.

There are other linking programs out there. TILP is pretty good. You can download it here. You have to pay attention while installing it because it requires GTK2+. It will run the GTK2+ installer after its installer by default. When going through the GTK2+ installer you MUST enable the 'compatibility dlls' checkbox or TILP won't work. I just installed it on my Windows 10 partition and it works fine for me (at least it launches, I haven't tried sending files with it) so if it doesn't work for you, chances are you missed a step while installing. If that doesn't work even after a couple ram resets, you might try looking around on the internet for other linking software. Its possible that your link cable or other hardware is bad.

If you just want to send things to your calc, resetting all memory might fix things. But that will wipe anything in flash.

still won't work

Then you are out of luck. If you write out a detailed list of what you have done, what software and hardware you have, I might be able to find something you have missed. But so far all you have told me is that you have a TI83 and it won't work.