I replaced my old (antique) 2.4 D-Link router with a new D-Link N300, DIR-615. My new Windows 7 laptop wirelessly connected immediately after I ran the
CD and set up networking. However, now my 2003 Toshiba and my desktops will no longer connect to the internet although it shows my network. I'm actually connecting my Toshiba laptop via Cat5 cable (although my desktops won't oblige). My older machines run XP. Could it be the drivers? I have no clue; my "computer guy" wants to reformat the hard drive (always his solution, it seems).
There can be issues with older 802.11b and even 802.11g wireless adapters and newer 802.11n routers. But the problem could instead be to do with router wireless LAN settings -- like Access List being enabled and set to exclude anything not listed. It could be to do with wireless mode setting or it could be something as simple as password.
Connect the computer to the router with an ethernet cable.
See the literature which came with your router for how to access the user setup screens in the router. Once in go to wireless security and review or renew the wireless security type and password. WPA PSK TKIP is the most common security type in use. Make a note of the SSID or change it to one of your invention.
Go to wireless mode and ensure that it's set to a protocol matching your computer's wireless adapter (mixed mode is a safe bet).
Check for a setting often called Access List that includes or excludes users by identifying the MAC ID unique to their wireless adapter. Disable that.
Disconnect ethernet cable.
Go to the computer's wireless networking setup screen and see if you can detect the router's SSID (wireless call sign). Select that network.
Apply the wireless security type and password to the computer's wireless networking setup screen.
Since the computer is definitely getting a connection you should go check the ip and dns settings. If you computer was setup with a static ip that was on a different than the default ip on your new router you would be getting this issue.
And it could be a security issue for the laptop wireless. Older wireless adapter were not made to support wpa2 or newer and if that is what you switched to when you installed the new router, it could be causing the wireless problem.