Have you recently installed anything - especially anti-spyware such as AdAware? This can cause a problem with TCP/IP.
1) Click Start
2) Run
3) type in CMD
4) In the DOS window (as Stephen said), type in ping www.google.com
If DNS (Name look-up) is working then you should get a reply along the lines of:
Pinging www.google.com [216.239.59.99] with 32 bytes of data:
Reply from 216.239.59.99: bytes=32 time=61ms TTL=246
Reply from 216.239.59.99: bytes=32 time=45ms TTL=246
Reply from 216.239.59.99: bytes=32 time=76ms TTL=246
Reply from 216.239.59.99: bytes=32 time=76ms TTL=246
Ping statistics for 216.239.59.99:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 45ms, Maximum = 76ms, Average = 64ms
If it's not working then it will either say it could not find the host or the host is not responding.
If it's the latter then in your browser type:
http://216.239.59.99
That's the IP Address for Google. Does that work?
Assuming it doesn't then type in the DOS Window:
ipconfig /all
It will return similar to this:
Windows IP Configuration
Host Name . . . . . . . . . . . . : Main_PC
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : Belkin
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . : Belkin
Description . . . . . . . . . . . : 3Com EtherLink XL 10/100 PCI TX NIC
(3C905B-TX) #2
Physical Address. . . . . . . . . : 00-10-4B-C1-BC-CB
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 192.168.2.3
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.2.1
DHCP Server . . . . . . . . . . . : 192.168.2.1
DNS Servers . . . . . . . . . . . : 192.168.2.1
Lease Obtained. . . . . . . . . . : 23 October 2005 12:36:27
Lease Expires . . . . . . . . . . : 19 January 2038 04:14:07
Look for DNS Servers. Do you have any entries there - there should be at least one, more likely two.
If there are entries then type:
ipconfig /flushdns
then reboot and try IE again.
Report findings as there's other stuff we can try.