New Dell Inspiron 3847 could not install

Yesterday I purchased a Dell Inspiron 3847 desk top. After I turned on the computer received a normal message for set-up verifying location United State, English and I choose Pacific Time and pressed next. I received message on blue screen "we are setting up your computer, this may take a while". Then after a few minutes the computer screen went from blue screen to flickering multi colors. I had no choice but to turn off the computer, wait and when I turned the computer back, on, I received message - your account has been disabled and then message defaultuser 0, with message insert key disk to reset. Which of course I do not have.

What happened? 

I took it back to Best Buy and they are not familiar with the problem. Also Best Buy La Quinta CA gave me a very hard time and accused me of placing a virus on the computer. I said really I just plug it in and turned on the computer.

Please advise. I did nothing else and no information was placed on the computer.

I would appreciate a relay,

Sincerely,

Copper