Networking issues

Hello my name is Barrett. I'm having really aggravating networking issues and I was hoping somebody out there could help me. So I have a desktop(acting as host) thats running xp m.c.e. 2004 thats hardwired to a linksys range plus wireless router. i also have 2 xbox 360's connected; one hard wired, and one wireless. Lastly, I have a laptop running windows 7. Everything was fine with my network until i got my laptop. when i first bought it, it had vista :/ The 1st problems I encountered was that if my 360's and desktop were online before my laptop connected, they would all get kicked off and I would have to reset my modem and router and then connect the latop first. Well i upgraded the laptop to windows 7 and it doesnt kick the wireless 360 off but now my wired 360 and wired desktop WILL not connect no matter what i try. Can somebody please help me? I am about to go insane. lol

 

Make sure that the Router can provide enough IPs by its DHCP server.