Windows Vista Server not found

OK, here goes, with as little french as possible
Click start and type ncpa.cpl into the search box and hit the enter key on your keyboard.
Now on the resultant page titled Network Connections you should see any and all network adapters installed on your system, since the link you provided didn't even tell me if you have a network adapter on your system I will only guess that you may see
Something called "Local Area Connection" which represents your wired connection, if you are using this then select it then right click it and choose properties
on the resultant page titled Local Area Connection Properties in the middle frame you should see
Internet Protocol Version 6 (TCP/IPv6) uncheck the adjacent box to the left of those words
Below that you should see
Internet Protocol Version 4 (TCP/IPv4) select/highlight that and click the properties button below the frame
On the resultant page Titled Internet Protocol Version 4 (TCP/IPv4) Properties
Leave the top radio button that says Obtain an IP address automatically alone that's fine
Nearer to the bottom you should see whats called a radio button that you should be able to select that says
Use the following DNS server address click that button and
In the Preferred DNS server: Box enter 8.8.8.8
In the Alternate DNS server: Box enter 8.8.4.4
May help if as I suspect the router is having trouble with either IPv6 or DNS forwarding sometimes they do, if not it won't hurt anything and is easily reversed.
EDIT: If you are using a wireless connection then disable the wired adapter, by right clicking on it and choosing disable and apply these setting to the wireless adapter.....likewise if you have a wireless adapter and not using it, select, right click and disable that.