I bought a license for Windows 7 Professional 64-bit from an authorized Microsoft reseller, and was given a product key and a link where I downloaded the .iso file from the reseller's website. When I initiated the install in Parallels Desktop, setup started normally, but soon there was a window stating, "A required CD/DVD drive device driver is missing. If you have a driver floppy disk, CD, DVD, or USB flash drive, please insert it now." There are options to Browse or Cancel. I can't seem to get beyond this point (there is no "Ignore" or equivalent), so all I can find to do is to abort the install. Is this a known problem when installing Windows 7 in Parallels Desktop? I've done a number of installs of other Windows versions (10, XP, etc), and have never seen this error before.