kaon:http://doc.qt.io/qt-5/supported-platforms-and-configurations.html
Qt 5.6 LTS supports Windows XP (deployment only) until March 2019.
Qt 5.7 will support Windows 7 and upwards.
I would recommend you to continue with Qt 5.6 LTS if you need to deploy to Windows ..
(2016-07-16 08:00) 