Since I am in a Microsoft program at my local community college, I can get a lot of Microsoft products for free via DreamSpark. However, nearly everything on DreamSpark is in an ISO format (Microsoft Project 2013 offers a web-based installer or ISO download). The hassle with ISO files is after you take the time to download them, you need to then spend more time burning them to a CD/DVD/BD or USB drive (after spending even more time trying to locate said media).
Not with Windows 8/8.1! The process is so much simpler. After you download your ISO, Right-click on the .ISO file and select “Mount” . The extracted file list will appear. You then click the appropriate setup/installation file and away you go.