You forgot to tell that your browser is Mozilla/Firefox. That means that there is a barrier between your PC and the target site. The causes could be either from your PC or external (ISP, routers in the paths, target server down, etc.). In order to identify the culprit try the following things:
1. Try to open them with Internet Explorer
2. Search for Hosts file under c:\windows\system32\drivers\etc folder.
Open it with Notepad and see if there are entries for those sites.
3. Use ping (for default gateway and dns) and tracert (for the final site).under command prompt.
Trying to unweave, unwind, unravel
And piece together the past and the future,
T. S. Eliot
What causes me to get this message "operation timed out when attempting to contact" web sites, such netscape.com, cnn.com and many others. These sites will not download.