It’s best to leave the USB connected until installation is completely finished. Just be sure to press the key displayed on the boot screen to enter the “boot menu” to temporarily select to boot from the USB flash drive instead of going through BIOS to set the USB flash drive to be listed first in boot priority.

When should I remove USB when installing Windows?

Early on in the process Windows will copy all the files it needs from the USB drive to your hard drive. Typically when the first reboot starts, you can remove it. In the unlikely event that the installation process needs it again, it will ask for it.

Do I need an empty USB to install Windows?

Technically no. However, depending on how exactly are you going to create the bootable USB drive, it can get formatted by the tool you use. … But, making a bootable device using media creation tools like rufus or the Windows Media Creation Tool, recommends to have the USB or the media to be flashed empty.