I have done the below twice, with a DBAN wipe on both USB flash drives just to make sure nothing was retained between tests. The drive I used for an ersatz CD-ROM was a Lexar USB 2.0 8GB and the one I used as a hard drive was a SanDisk USB 3.0 16GB.
I downloaded the ISO for amd64 from TCSScreening, the website referenced by Intel Downloads, and installed it onto the Lexar using Live USB Creator, something I have used many times before. Then I inserted it into a DZ68BC / i5-2500k system and booted up Fedora. As soon as it finished booting, I inserted the SanDisk. I double-clicked on the Install To Hard Drive icon to start the process of installing Fedora. Soon afterward the system got to a screen which allegedly allows the user to set both root and user passwords. This is shown on page 17 of "The Intel Processor Diagnostic Tool in the Fedora Live OS - User Guide". However, pay close attention to that screen capture. It shows that the root password has already been set and a regular user of testuser has been created. Neither should be there; it should show that neither a root password nor any user has been created. I set the root password to something of my choosing. I overwrote testuser and used my first name, along with a password of my choosing. Then I finished the installation.
However, when the new system was rebooted and I attempted to do a su to perform some root duties, I could not do so because the root password was not what I set it to. I assume it was hard-coded and ignored my attempt to change it. I was able to logon using my first name, but I could not do anything which required root authority.
In my first test, I unchecked the box on creating a regular user which gives it admin authority, but in my second test I knew better and left it checked to give myself another way in. I was able to use that user to change the root password. And "The Intel Processor Diagnostic Tool in the Fedora Live OS - User Guide" does not specifiy what the hard-coded root password is.
I looked in /home and noticed that there was only one directory -- for testuser! When I opened a terminal and did a PWD, the response was /home/testuser. So both root and testuser were fairly hardcoded. I was able to rename testuser to my first name via su Then I tried one last thing. I executed "yum groupinstall GNOME" which should have converted the LXDE desktop to a GNOME one. The messages appeared to indicate that the necessary files were downloaded and installed, but after a reboot the desktop remained LXDE. After another reboot, I was unable to logon (after entering my password, the system flashed and then returned to the logon screen).
I have played around with Linux recently, on Fedora, Debian, and Zorin OS. My usual method of installing is to use either Rufus or Live USB Creator to build a Live-USB and then install Linux onto an SSD or USB 3.0 flash drive. The day before I had installed Fedora Security onto the same SanDisk drive I referenced above, with no problems.
If Intel does not intend to fix the aforementioned bugs, the Install To Hard Drive option should be removed from the release, making the ISO usable only as a Live-USB / Live-CD. It'd be nice if Intel supplied the RPM packages on Intel Downloads so the installation could be done on an existing Fedora system.