Error setting up base repository, under install source.

I booted up the machine and started the install process (new hardware, never had an OS installed on it) and immediately hit a snag. There are a couple things I needed to deal with on the main install screen. One, it asks me to pick the boot disks, so I checked all 4 of them and chose RAID 10. So far so good, but then the fun begins.

The main problem I am running into is that it lists the repository as an error. It says under Installation source, error setting up base repository. If I click on it, it initially shows something like /dev/sde1/ (14.6 Gig MB) EFI system partition as one choice, which isn't selected when I go into that screen, and on the network as the other option, which is selected but greyed out I presume because the NIC isn't enabled yet, that is on another screen.

I tried being clever and copied both of the .iso files to another USB drive and inserted it in the machine, but it doesn't appear to see it. One thing I noticed when I was downloading the software after I purchased it was there were actually 2 files, I grabbed them both: rhel-workstation-7.4-x86_64-boot.iso and rhel-workstation-7.4-x86_64-dvd.iso. I made the bootable USB out of the 2nd one, not sure why there were 2, the boot .iso is about 470 meg, and the other is about 4.4 gig, and it obviously boots and starts the install from it.

So... this thing isn't smart enough to use the files that it is booting up from, to do the installation with? Am I possibly missing something?

It says in the help file of that page, that if installing from a USB device or DVD, it is supposed to automatically detect it, and this error shouldn't appear. I can't find any way around this dilemma. Any suggestions would be appreciated, I'd sure like to get this box loaded and configured tonite.

edit Think I might have figured it out. After letting Google be my friend, I eventually came across a post that explained it:

Make sure you have not inadvertently tried to use the boot.iso for rhel7 as your installation media; it will generate the error you are reporting because the boot.iso does not contain any of the installation repositories virtualbox will need. Instead you need to download the dvd iso which is approx 3+ GB in size.

Well, pulled out the USB stick, put it in my machine, and did a properties of the entire drive. Turned out to be under 500 meg total.... Doh! So, re-burnt it, being sure to pick the dvd file not the boot file, and started over. System boots up, and wa-la!