Hey mate... a lot of the basic info has been covered already... but you might find that the reason you cannot connect, is that the router may not be setup correctly...
in USB mode, it is acting in a similar way to a normal modem, so your computer is effectively directly connected to the net... when using in Ethernet mode as an actual router, the router itself is connected to the net and acts as a gateway for your comp.
Unless the router is configured to provide your comp with an IP address (and possibly DNS server addresses), you will probably not be able to connect to anything...
The easiest way to check is to open up a command prompt: Start

Run

Type in: 'cmd' (without quotes)...
Then at the command prompt type: 'ipconfig /all' (without quotes)
You should see something like:
- Code: Select all
Windows IP Configuration
Host Name . . . . . . . . . . . . : hcp
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Broadcom NetXtreme Gigabit Ethernet
Physical Address. . . . . . . . . : 00-12-79-A9-76-1A
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 10.1.1.82
Subnet Mask . . . . . . . . . . . : 255.0.0.0
Default Gateway . . . . . . . . . : 10.1.1.1
DHCP Server . . . . . . . . . . . : 10.1.1.1
DNS Servers . . . . . . . . . . . : 10.1.1.1
Lease Obtained. . . . . . . . . . : Thursday, 1 May 2008 9:45:09 a.m.
Lease Expires . . . . . . . . . . : Thursday, 1 May 2008 10:45:09 a.m.
The important lines at the moment are:
Dhcp Enabled - this should be set to 'Yes'
Autoconfiguration Enabled - this should also be 'Yes'
IP Address - generally routers are configured to use ip addresses like 10.1.1.* or 192.168.*.*... if you have an address that starts something like 169.254.*.* you have problems...
Default Gateway: if your IP is 10.1.1.*, your gateway will most probably be 10.1.1.1.... if it is 192.168.*.*, your gateway will most probably be something like 192.168.1.1 (or possibly 192.168.0.1)
DHCP Server: should be the same as the Default Gateway
DNS Servers: This can be either the same as the default gateway (in which case the router is forwarding DNS requests), or it could be set to the DNS servers of your ISP (depending on how the router is setup)....
The most obvious indicator will be the IP address... if its the 169.254.*.*, then your router is not setup to automatically configure any PC's that connect to it... not necessarily a bad thing, but it means you either need to:
a. Setup the router so it will automatically configure any client PCs... (quickest, easiest solution)
or
b. Configure your PC with a static IP address, Default Gateway and DNS Servers etc... (will work, but is a bit fiddly and you will need to do it for every machine you want to add to the network)
If you have issues, post the output of your 'ipconfig /all' (screenshot or copy/paste) and we'll have a better idea of where the problem is.