Hey, I've bought a new TOshiba laptop (i think it ...

Looks like a IP connection problem, you may want to check this: First goto Run and type Cmd and hit enter to get to the command prompt. Type ping 127.0.0.1 to see if your network adapter will respond. This should help determine the status of your tcp/ip stack. Then try ipconfig/all and check the results there. Also try route print and see if you have an entry 0.0.0.0 with an IP address corresponding to your network adapte address from the ipconfig/all and your router/gateway address will show too. Try to ping your network adapter to see if you get a response. Try to ping your gateway address. Also try nslookup to check the status of the DNS server you are using. I'm assuming you are using the DHCP off of your router and not running a server yourself.

I'm guessing you are trying to access unsecured networks that were not configured by you.
Many wireless AP (access points), seem to be unsecure, but infact block all unwanted users (using a feature that allows them to set which MAC addresses are allowed to connect). In that case, it will look like you are connected, when infact you cannot accttualy use the net.
Another reason might be the distance of the AP. If you do not have a strong enough signle, you will not be able to connect (it takes a stronger signle to connect, than to surf after you are connected).