Also.. try this:

Start, then All Programs, Accessories, MS DOS

When DOS opens, type this in:

ipconfig /release

notice the space between the G in config and the / That is intentional

Then, enter:

ipconfig /renew

Make sure the space is there.

The computer should respond after the first ipconfig with:

IP Released: 0.0.0.00
or something like that

Then, the second time it should show your IP address

Then, if your using firewall software, DISABLE it and try to get on the site. Some firewall software may have gotten "hit" by the site and for some reason your firewall thinks your being attacked so it's blocking the site.