Your new router will have a different WPA password and SSID (network name) compared to your old router. Have you set the new router up? Each WiFi machine will need to reconnect to the new router and have its settings adjusted to match the new router’s settings.
First step, follow your new router’s manual.
Netgear Router setup wizard video http://kb.netgear.com/app/answers/detail/a_id/12873
Belkin easy setup page http://www.belkin.com/networking/wireless-routers/easy-setup/ – Router support http://www.belkin.com/us/support-article?rnId=6939
You need to set up a WEP, or better yet a WPA encryption on your wireless network so you are not leaving it open to all comers. WEP is weak security, only use WEP if you have a Nintendo or other device that doesn’t support WPA
You log into your router using the a web browser, type 192.168.0.1 or 192.168.1.1 (for different models of routers, this address will be different). This is easiest from a computer that is attached by a cable. You should have an admin password. If you have never set one, then it will be the default NetGear username “admin” and password -blank- or “1234”
(other brands use user -blank- and password “admin”)
http://kb.netgear.com/app/answers/detail/a_id/112/~/securing-your-wireless-network%3A-wpa%2Fwpa2-%28recommended%29
Go to the wireless setup portion of the controls, select WPA Personal, and enter a long passcode that you can remember. Write this down in the inside cover of your router user manual!! you will need it to log in from your wireless computers.
Consult the help screens of the administration interface for specifics or read the manual.
When you are done. change the router’s admin password to something other than the default. Write this down!!
http://www.pcmag.com/article2/0,4149,1277020,00.asp
Now, set your Wireless machine’s WiFi settings to match the password and SSID that you used for the router.
Vista http://kb.netgear.com/app/answers/detail/a_id/95/kw/configure%20client
XP http://kb.netgear.com/app/answers/detail/a_id/111/kw/configure%20client
Win 7 http://kb.netgear.com/app/answers/detail/a_id/13267