Most of the times this is caused by an antivirus program blocking Adobe Reader from connecting. Its not only from antivirus, but antispyware and firewalls also.
Try temporarily disabling this type of software, to see if it makes any difference.
Also, definitely check out this link from adobe. It gives you an entire overview of ways to solve your exact question.http://kb2.adobe.com/cps/328/328233.html
I hope this helps!
Windows Outreach Team