I'm using Parallels Desktop 9 (latest version) on my Mac (10.8.5) and installed Windows 8.1 Preview successfully. Yesterday I downloaded Windows 8.1 RTM (6.3.9600.16384) and tried to install a new VM but encountered an error when the installer let me select the hard drive, said 'A media driver your computer needs is missing. This could be a DVD, USB or Hard disk driver. If you have a CD, DVD, or USB flash drive with the driver on it, please insert it now.'. I think this is because Window 8.1 installer didn't find any hard drive on my virtual machine. But I don't know how to solve it. I installed successfully on Virtual Box but failed on Parallels. Below is the error screen.