Start -> Run...
Type "cmd" and press ENTER
On the black window, type "ipconfig" and press ENTER, that should give you your IP address. Prolly something like 192.168.xxx.xxx or perhaps 10.xxx.xxx.xxx
Now type in "route -n" and ENTER again. Look for a line saying Gateway or maybe just "gw". Note this number, prolly something like 192.168.1.1, 192.168.1.254, 10.0.0.1, or similar.
Type "ping xxx.xxx.xxx.xxx", where all the xxxs are the number you got from the route bit above. If you get a reply, you can talk to your router, which is good.
Now try "ping 4.2.2.1". If you get a reply, you can get out to the internet, which is good.
Now try "ping google.com". If you get a reply, then you can get out to the internet, and your DNS settings are good.
If all of the above went Ok, your problem is with your browser configuration. If any of the above failed, report back.
Somebody please correct the instructions above as needed. I'm not a Windows type[*] and only vaguely remember the process through sheer repetition.
[*] Just a basic Unix user. I only ever wrote a couple device drivers.