I have a friend who has set up a new wireless/modem which ip address is 192.168.1.1 and when you go command run cmd and put in ipconfig /all the DEFAULT gateway shows up 269 .254.40.90 which is the same as the ip address. Should it not show as 192.168.1.1 being the default gateway.
They do not have a STATIC IP address. The computer that I am suing to send this message is also on a home network and when I check the ipconfig the default gateway shows the IP address of the modem. Any ideas would be a great help. Ojas
1. Modem. Find the user guide for the make and model number of the equipment. There should be setup and configuration information available. I'm not sure whether we're talking about a modem, wireless access point, router, switch; or all of those components integrated into one box. This may be because I'm not familiar with "wireless" modems. My experience is with a "wireless" home router.

2. Automatic Private IP Addressing (APIPA). I suspect you misread or MISTYPED the gateway address of "269.254.40.90". You're probably GETTING addresses within the APIPA range of "169.254.x.x". That would suggest their computer is configured to "Obtain an IP address automatically", but is unable to get TCP/IP configuration information from a DHCP server either because it's unable to find one, or the DHCP server is unable to comply with the REQUEST. At this point Windows may assign itself an IP address from the APIPA range. Your friend may set the TCP/IP configuration information manually or enable the local DHCP server within their home router (modem?).

3. Enable "DHCP Server". Have your friend locate and enable the "DHCP Server" capability for their local area network. For my home network, it is located among the web configuration pages of my wireless home router which is accessed by its local configuration IP address; e.g. "192.168.1.1".

4. Reference(s):
http://www.home-network-help.com/index.html