Hello,
My problem is when I am connected to the internet with a cat5 wire, sometimes I lose connection. I then disconnect the cat5 wire and turn on my wireless connection and I am connected again. Do you think there is a problem with my wireless router or my switch?

I have a DSL modem connected to a 4 port Linksys wireless router and a Linksys 8 port switch connected to the wireless router.

Thanks in advance for your help.

Do you have any disconnects if you go over the wireless connection? Have you tried hocking up the cat5 directly to the wireless router instead of the switch? If the problem still persists then you can take the switch out of the equation. I assume you have more than one computer and the problem will show up on all of them that would eliminate the NIC as trouble maker and faulty wiring. So try going directly over the router if the problem goes away then there is a problem with your Switch, might as well check the cable going from the switch to the router.
Another question would be, do you lose complete connection (to all other PC) or is just your internet gone?

You can also check whether your cat5 cable is not damaged in some way!

Thanks for your help. I found the problem. Somehow the under Internet Protocol Properties (TCP/IP) the "Use the following DNS server addresses was checked. All I needed to do was check "Obtain DNS server addresses automatically"