如果你的Win10 ISO是2015年十一月之后的版本，可以直接用正版Win7，8，8.1的序号安装，不需要通过Win7升级。

As of the November 2015 build, an existing Windows 7 or Windows 8.1 product key can be entered during installation to activate the free license, without the need to upgrade first to "activate" the hardware with Microsoft's activation servers.
Source: https://en.wikipedia.org/wiki/Windo...e_upgrade_offer