First, opening the URL from here (using Win 7) is not a problem. I'd suggest that you get help from your computer manufacturer's technical support, as they would be most likely to know your software.hardware configuration and be able to tell you what might
cause certain URL's to be blocked.
I'd also suggest that you post your Windows 7 user problem in a forum for your topic. Here is a link to the Windows 7 Answers forums:
http://social.answers.microsoft.com/Forums/en-US/category/windows7