Windows 8 Activation behind a proxy

How to activate windows 8 behind the college proxy server? Error code : 0x8004fe33 I've tried netsh winhttp to configure the system proxy but no success.

The most common cause of that error code is a proxy requiring basic authentication but not configured to whitelist some specific URLS needed for activation. The suggested work-around for the user (in opposition to the proxy owner) is to use phone activation, by running "slui 4".