First, WIN 10 cannot directly modify WIN7. You need to format the whole hard disk and change it to the format required by WIN 10 (save the data yourself in advance).

Second, when did you buy the computer? If you bought a computer in the past year or two, then you should give it up. In order to better promote his system, Microsoft has negotiated with the hardware company about the computers it bought in the past two years, and it is not allowed to install Win 7 on the newly sold computers.

So even if you can install WIN7, it's useless, and all kinds of problems come out, such as unlimited restart, which will automatically restart after use. The reason is not the system, but the limitation of hardware such as CPU.

This is a marketing tool, and it is self-destructive. Because Microsoft's WIN operating system has already dominated the world. There is no substitute!