Lets take this one step at a time:
- First thing, go into Settings -> Control Panel -> Network Connections. What do you have listed there for interfaces? NOTE: You should be connected to your router with an ethernet cable when you do this.
- DOUBLE CLICK on the Ethernet interface and check the properties. It should say "connected."
- Switch to the "Support" tab and check what it has listed there for "Address Type", "IP Address" etc..
- If it say "No connection", try right clicking and selecting "repair."
- Also, let us know what other interfaces are listed. In my picture I have a 1394 interface. You may also have some sort of USB modem interface lsited.
Here's a screen snapshot of what I'm talking about
:
http://i43.tinypic.com/209fs6q.jpg
Vista will be a little different, you may have to switch to Classic view... sorry, I'm not a Vista user.