I am trying to re-install Win 7 on a laptop that I had to erase due to a virus. I have a OEM OS disk, and the laptop doesn't have an optical drive. I have to find a way to make a USB copy that will install Win 7 onto the little laptop. If I use the WIn 7 USB DVD Download Tool, it's looking for an ISO image file, and I don't have one. I DO have an OEM disk, and the laptop has its original key sticker on the bottom. How can I make an ISO image? Can I use the OEM disk to make an ISO image so that I can get this process going?