Slow speeds, etc.

I'm a complete rookie to switches so please bear with me.

I have a Linksys EZXS88W switch and am utilizing it so I can run internet to 2 computers. (I think I bought the right thing...?)

1. Computer #1 has internet access but is very slow. My usual internet connection is 15Mb/s down but after connecting through the switch, it is now at approximately 500 Kb/s. What can I do to resolve this speed issue?

2. Computer #2 is unable to connect to the internet at all. I have swapped the wiring between the 2 computers to ensure the ethernet cable was not to blame. I also swapped the 2 plugs to make sure the #2 port on the switch was not at fault. I have also tried rebooting that computer as well as tried to disable/enable the connection in network properties. Trying and ruling out those 4 possibilities pretty much exhausts my troubleshooting in that department. Why am I not able to establish a connection on computer #2?

I am going to guess that you have some sort of cable internet but that aside...if you are plugging your modem directly into a switch, you are trying to distribute 1 IP address that your ISP gives you to many different computers. There are 3 ways to go about this and that would be to buy a router..., install a second NIC in your PC and utilize ICS, and last is buy some more IP's from your ISP for each computer on your network. I wouldn't recommend the last one.