You have your computer ready to go, but you lost your disc. Well now you can navigate to Microsoft Software Recovery. If you purchased a retail copy of Windows, enter it on the site and they will give you an ISO file. Lets say you do not have your disc key. You can get it from your current computer or from someone else. You will have to get a program called Magical Jelly Bean KeyFinder, but if it doesn’t work for you can find a lot of other key finders on the internet. Once you have downloaded the ISO file you can use the Windows 7 USB Download Tool.