If you can ping an address on your local network (e.g. 192.168.1.1, but
this will depend on your network), then you have basic network
connectivity.
If you can successfully ping a numeric address on the Internet which is
set up to respond, you are connected to the Internet. Any such address
will do; e.g. 195.149.20.145
If you can successfully ping an Internet named address which is set up
to respond, your DNS server is OK.
www.nildram.co.uk will do
If all the above work, a web browser should work.
Otherwise try setting your gateway address manually, as soemone has
suggested. You will need to know your network's gateway ddress.
Set your DNS address to a working DNS server (any DNS server on the
Internet should do, though you would normally use your ISP's).
HTH,
--
Michael Salem