I connect my xbox 360 to my router by, cat5 cable now the internet on my computer times out frequently, ideas?

My internet is running into a Netgear router WGT624v3 then into my computer and then a I ran another cat5 cable to the xbox, if the xbox cable is plug into the router, my internet access on the computer is slow and say "server cannot be found frequently"? any ideas?I connect my xbox 360 to my router by, cat5 cable now the internet on my computer times out frequently, ideas?
Each device connected to the internet takes a share from it.



So if your on xbox live or downloading something, it will make the PC's connection seem slow.