|Unless the site has been put in Restricted Sites or blocked by a Hosts file then it has to be a server issue. Hosts file is in C:\Windows\System32\drivers\etc. Try temporarily renaming the hosts file to hostsx (which disables it) and see if that helps. Close browser and reopen to check it out.|
You could also try installing Firefox browser just to prove the point.
Please come back and let us know how you got on.