My Model H2G2-42 ( I am not sure which Gen. it is.) I am unable to reinstall it on my latest TV Via my Desktop. I do not have a smart phone or tablet. I believe if I buy a new Chromecast it will still not work with my computer. Desk tops are still in use.
I'm sorry, but you can't use a computer (desktop or laptop) to setup a Chromecast device.
You used to be able to but Google removed that ability years ago.
You have to use the Google Home app on a compatible phone or tablet. There is no other way to do the setup.
Once you have it setup, you can still CAST from a desktop using the Chrome browser.