Start any Windows Accessory program such as Paint or Calculator and open the program's Help dialog by pressing IF1] or the menu item' Help I Help Topics'. Right click on the title bar in the help window and select the context command 'Jump to URL'.
Enter the complete Web address in the subsequent dialog as and click 'OK'. This should bring up the desired website in the right window pane. You can now navigate through it using the context commands, accessible by right clicking on the website pane.
NOTE: Calling up websites via the Windows Explorer uses Internet Explorer in the background and is thus not a way to access restricted websites.