I have this switch that I bought a while ago and had this computer and my daughters, up stairs, hooked up to it.  I dusted off my old work laptop and installed Windows 2K so my son could use it.  When I went to connect it to the hub, or switch, or what ever the hell it's called, now only one computer works on the internet at a time.  I bought a 50 foot CAT 5 cable but even with that off and back to just mine and my daughters on, I can still only get one to have internet access at a time.  It's like when I unplug the cable modem power and plug it back in, the first computer I access the internet with is the one that gets it and the others won't see a conection.

What I foul up?

a hub or  switch will not work for what your are doing. you need a router link

a router will allow 253 computer's to surf on a dsl or cable internet connection.  

Do you mean the router?

Try running the network setup wizard on all of the machines.

Oh.

Thanks.

Why did this switch thing work with this and my daughters for the last 4 months?

Is because they both run XP?

your isp(internet service provider) gives you 1 ip address to use for the internet(sounds like a dynamic ip).  so it will work on one computer at a time.

 to add another computer to the internet you must get a router then it will allow multiple systems to surf at the same time.  

Yep, you can get a 4-port router with a hardware firewall for $10 after rebates, it actually works out to about $15. My son got a D-link 604.

Something must have changed with the way your ISP hands out IP addresses.

Switch, hub, and router work differently.

With a switch, your ISP sees each of the computers attached to the switch, and will have to assign each computer its own IP address.

With a router, your ISP sees only the router, and assigns it one IP address.  The router sets up a network with all of the computers plugged into it, and the ROUTER assigns each computer its own IP address.  

Looks like you need a router.

BTW, in the past I used a switch with 4 computers hooked to my DSL modem.  No problem, and it will work that way now.  However I now have a wireless router replacing the switch that was used previously.