how the connection is being attempted (wired or wireless) and whether the modem/router is your or some neighbors, as well as the Operating System on the problem computer and any error messages being presented it will be difficult to offer suggestions.
I am not able to change the IP address; manually or automatically. We moved to a new place and the problem started the 1st day, Other two computers work fine. But the third one can't connect to the web.
What is happening?