Try this. Read the top post in this forum and set it up our way.
Link -> http://forums.cnet.com/5208-7589_102-0.html?forumID=62&threadID=264135&messageID=2584349&tag=forums06;posts
Specifically posts 2 and 3 and if you have Vista, turn off the Broadcast Flag in Vista.
I have been battling the wireless internet at my apartment lately. We have a linksys router and it used to run great. Its about 2 years old and my wireless speed used to stay at 54Mbps. Now it jumps around and constantly hits single digits. I tested the internet with a wire and it runs perfect so the cable modem works fine.
My quesiton is, will my internet connection always be slow due to the fact that I live in a busy apt. complex with about 10 other wireless routers in range or do I have a faulty router?