easiest things to do is to first check to see if the computer recieves an IP based on the routers DHCP,
Where and how do I do that?
easiest is go to
Start-> Run type: cmd
type: ipconfig
Look for something like
"Ethernet adaptor Local Area Connection LAN:
..."
so for me as example output (I have my adaptor names as PlasmaInfusing, this is normally just Local Area Connection for a name):
Ethernet adapter PlasmaInfusing LAN:
Connection-specific DNS Suffix . :
Link-local IPv6 Address . . . . . : fe80::f129:dbd0:7188:552b%10
IPv4 Address. . . . . . . . . . . : 192.168.1.3
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1
Look for that IPv4 address, or if your on XP just IP address, if its blank or perhaps 0.0.0.0 then you aren't getting an IP address, try putting it in a different port on the router.
IF that is the case then type
ipconfig/release
then
ipconfig/renew
if you dont get an address then the router isnt dishing out an IP next check in your router and somewhere (I cant say exactly where It differs per every router) look for Connection status or list of connected devices and see if your computer desktop is listed while your on
Also, if while your getting no internet you are able to connect to the router then its a problem not with the computer but with the router or modem more than likely, if not then its probably the computer adaptor or wire or basically anything on any other side of the router
Let me know if that was confusing at all, Im operating on 5 hours sleep atm.