Connected to router but have no internet

So here’s my situation… I had ATT as my isp and they raised their rates so i switched to time warner. internet was working fine before i switched. now i’ve got the same wireless router connected to a new modem and my laptop gets wireless internet just fine, but my desktop does not. my desktop had wireless just fine before and i have internet on it if i use an ethernet cord. my computer DOES say that i am connected to the wireless router, but i have limited or no connectivity. i have the right network key and the router security setting have my MAC address programmed into it so that i can access it, so that’s not stopping me. whats wrong?