4+ Circumstances You'll Need Bootable USB Drive. Your computer crashed and won't boot upYour computer hasn't been reinstalled for a long timeits running slowly nowYour computer has a virus. You need to clean the virus and reinstall WindowsYou are new to computers and need a computer repair toolBoot Menu instruction (refer to user manual): 1. Plug-in USB Drive2. Power on and Press boot menu key repeatedly (Boot Menu Key below) 3. boot menu will appear (Ensure "USB boot" is enable in BIOS)4. choose usb drive from boot menu, UEFI USB" is preferred selection