If your signal is constantly dropping, an ipconfig may show you a 169.254.x.x address which is called an APIPA address - used for ease of home networking.
Make sure you have a connection first (keep your eye on it carefully to be sure you get the correct information)
Open a command prompt by clicking on Start -> Programs -> Accessories and then Command Prompt (I had to enable "run" on the vista start menu, which is why I give the navigation route) or hold down the windows key and press "r"
followed by typing in "cmd" - without quotes.
Type in ipconfig into the black box, and it will return with information relevant to most likely 2 network adapters. Look for the one listed as "wireless" if you're not cabled up, and you will see 3 things listed:
IP address -> your computers network address
Subnet mask -> by definition, it's where you computer "is" on the network
Gateway -> The gateway address is typically a router address and in the case of home users 99% of the time, your link to the configuration of the router.
Enter this Gateway address into Internet explorer's address bar and press enter.
You may need a user ID and password to connect onto your router. this should be in your manual.
Good luck.