It sounds like your laptop has an ip address conflict -- it has the same address as another device that is on your network. You need to check all of your addresses and change one so there is no duplication. You can look at the router dhcp assignment table in your router and on each of your computers.
One way in Windows to check the address is to type "ipconfig" in the command prompt box and write down the ip address that is used for each.
You can also check in your laptop Network control panel to see if the ip address is set to a static address -- best to let your router assign it one dynamically so it won't conflict. Either that or give it a static address within your network but outside the range assigned by the router's DHCP...