See here for how to reach support (FAQ) - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2421771&SiteID=2
Use the option that you are a trial user and specify that the problem is on another computer so that you can submit the support request.
Since your problem involves connectivity for both the original update issue and now the installation problem, I would check your IE settings - Tools/Internet Options/Connections/LAN Settings and uncheck all options. If this does not resolve it, check the autodetect box and try again.
This assumes that you are on a high speed connection. If you are on dial-up, make sure that no download accelerator is enabled.
Finally, but actually first of all, make sure that nothing is interfering with your connection - no other firewall, parental security, etc, that might be blocking the connection or serving as a proxy.
-steve
