Ahha! I have just overcome this problem myself.
Being a highly tech savvy I immediatly assumed that this was a most complex and difficult problem to overcome. So naturally I started looking at things like port 80 and internet proxy options.
But alas, it was my anti-virus which caused this error! A most dispicable fiend.
I have Avast anti-virus so I will tell you how I disabled mine.
Open up the program and its friendly user interface, go to Settings at the top. In the newly opened Settings window go to the left and chose Troubleshoot from the nice little list at the bottom and then in the check box area that has appeared uncheck the Avast defence module. Now hit OK / APPLY.
Now you may close Avast completely. (Since exitting out only hides it in the background)
Hit control+alt+delete and open the Task panel.
Scroll across from programs -> processes,
Now find the AvastUI.exe or something along those lines and end that process.
Avast! It is now closed! and you may Restore/Update at will!