1, Download Windows 7 iso file, you can download from this page: http://www.yusoftware.com/microsoft-windows-7-full-version-free-download/ or ask us send you a download link from Microsoft Official Site. After you finishing the download, you will see a iso file, please extract it to the root folders of a a partition. (Not the partition which have installed the system you are using now)
—— You can use Winrar to extract the ISO file. Winrar download: Check Here
2, Download Windows 7 install tool nt6 hdd installer: Click Here
3, Run the nt6 hdd installer, you will see this software Interface,
Please Click “1. 安装”, you will see this Interface,
Please click “2. 重启”，your PC will restart, and you will see this Interface,
Please choose Nt6 HDD installer Mode to install the Windows 7.
In the proccoss of Install Windows 7, you should choose to install WIN 7 position in, please choose the Partion you want to install, then click “Drive Options(Advanced)” to format it.
Any problems please leave a comment, I will help you solve it.