If your computer doesn’t have an optical (DVD) drive, how do you install Windows?

• Go to another computer with a DVD drive.
• Use ImgBurn to create an .ISO file from your Windows installation DVD. (you can use an alternative application if you want)
• Don’t bother with Windows 7 USB/DVD download tool. Use Rufus. It’s perfect. You give it the .ISO file and a flash drive (your USB drive) and it will turn your flash drive into a Windows installation media.
• Boot from the flash drive and install Windows.