It is possibly a problem with your Internet Service Provider (ISP). Their Domain Name Service (DNS) servers may not be providing the correct results or their routers may have a fault in their routing tables or a connection problem to some parts of the Internet.
Here is what I would do:
Check the name
Open a command prompt window (start, all programs, accessories, command prompt)
type nslookup www.bbc.co.uk
and press enter.
You should get an answer like this
Server: ns0.ispname.es
Address: 1.2.3.4
Non-authoritative answer:
Name: www.bbc.net.uk
Address: 212.58.246.93
Aliases: www.bbc.co.uk
The first part is the name and address of one of your ISP's DNS servers.
The second part should be the same as above - although the BBC probably have many web-servers so the actual IP-address may change from time to time.
Check the address
type ping www.bbc.co.uk
and press enter.
The response should look like this:
Pinging www.bbc.net.uk [212.58.246.91] with 32 bytes of data:
Reply from 212.58.246.91: bytes=32 time=50ms TTL=54
Reply from 212.58.246.91: bytes=32 time=51ms TTL=54
Reply from 212.58.246.91: bytes=32 time=51ms TTL=54
Reply from 212.58.246.91: bytes=32 time=49ms TTL=54
Ping statistics for 212.58.246.91:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 49ms, Maximum = 51ms, Average = 50ms
Check your ISP's routers
Type tracert www.bbc.co.uk
and press enter
Tracing route to www.bbc.net.uk [212.58.244.66]
over a maximum of 30 hops:
1 <1 ms <1 ms <1 ms router.local [192.168.0.254]
2 45 ms 43 ms 44 ms router.zaragoza.ispname.es [88.2.3.4]
3 44 ms 44 ms 43 ms router.madrid.ispname.es [2.3.4.5]
4 46 ms 51 ms 44 ms router.other.ispname.es [7.3.5.22]
5 44 ms 45 ms 46 ms router.whatever.ispname.es [11.2.5.6]
6 50 ms 50 ms 49 ms router.somthing.ispname.es [34.45.5.6]
7 147 ms 50 ms 49 ms 99.77.254.140
8 49 ms 49 ms 50 ms 212.58.238.129
9 50 ms 49 ms 49 ms 212.58.239.58
10 51 ms 50 ms 54 ms 212.58.251.44
11 50 ms 49 ms 49 ms bbc-vip111.telhc.bbc.co.uk [212.58.244.66]
Trace complete.
(I have disguised the details of my on ISP's names and addresses)
If your PC produces error messages, it is time for the last step.
Phone your ISP's help-desk
You already pay them to provide help with this sort of problem.
Update your question with more information
You can cut & paste your own results from nslookup, ping and tracert. In the command prompt window, click anywhere with the mouse right-button and choose "mark" from the context-menu.
Now use the mouse's left-button to select the command and response text. Press enter to copy the marked region to the clipboard. Paste into your question between lines containing <pre> and </pre>.
Have you looked at our Community FAQ How to diagnose not being able to reach a specific website?
– nhinkle – 2011-03-27T02:36:01.743