The new router/modem says "this web page is not available , ERR_CONNECTION_RESET" when I open a web page and use its login address and in windows trying to make a new internet connection it says "Connection failed with error 651". My previous modem has.... "Connection-specific DNS Suffix . : Belkin" in ipconfig I was hoping if I deleted the Belkin software I could install the new modem/router.
How are you trying to access the new router? It should be just through a browser.
But yes, uninstall the old s/w. Not sure if that will make any difference, but you don't need it any more.