Hi there,
I received the same issue. I was however working with Win 7 and Outlook 2010 on Premise. What caused the issue for me was that the user was connected via a network cable and using the Wireless at the same time. The two different proxy settings interfered with each other and caused CRM to fail.
Once disconnecting from the Wireless, the install continued.
Check your proxy settings are correct as this might be causing the issue.
Regards
Barry