Using a Linksys router as an access point

go Start then Run in XP - (Windows key plus R in Vista and Windows 7), then type in the following, including all the spaces:- cmd /k ipconfig /all -- then press Enter and from the black form that shows up, take a note of the numeric code beside the word "gateway" -- usually something like 192.168.0.1. Type exit to close the black form.

connect the router to be converted only to a computer via network cable and log in

setup the wireless security

disable the DHCP and change the LAN IP to match the gateway IP but ending in .253

finally connect one of the four LAN ports of the AP to the main router, do NOT use the WAN port.