Windows 10 Technical Preview for Enterprise：
KEY：PBHCJ-Q2NYD-2PX34-T2TD6-233PK
http://technet.microsoft.com/zh-CN/evalcenter/dn781239.aspx
Windows 10 Technical Preview：
KEY：NKJFK-GPHP7-G8C3J-P6JXR-HQRJR
http://windows.microsoft.com/en-us/windows/preview-download