How do I install a new copy of Windows 7 with a bootable USB?

I get stuck on the install guide which claims there's no "driver" to be found.

I've tried including Intel Chipset Manager and Driver in the USB drive - something to do according to http://superuser.com/questions/873781/windows-7-install-load-driver-error-lenovo-laptop - but I might not have understood how to do that properly.

The existing OS on the computer is Linux. And the computer model is Lenovo Y50.

You want to replace Linux… With Windows! Madness!

You can make a bootable USB with Rufus.
https://rufus.akeo.ie/

You might have to do a "custom" Win7 install. When it reaches a point where it is missing a driver, it will ask for you to load it (via USB). By default, a generic Win7 install just skips that step, then fails on restart (or fails to install)