|I can confirm that the web site does exist and is accessible.|
What makes you think Dell Support is blocking it?
If Dell were an ISP I could understand it but Dell aren't really in a position to block websites.
What is probably happening is that there is a problem with your computer that cannot find the web site and your browser which has been tweaked by Dell is redirecting you to their web site.
Which browser are you using. I would hazard a guess and say it is Internet Explorer. In which case try a different web browser.