The system was configured to only boot from the internal hard drive.  BIOS could not be accessed using any of the function keys or the escape key.  BIOS could not be accessed via the Windows 10 Update and Security options.  The computer would not boot from the internal CD/DVD or from a Windows 10 installation on a USB flash drive.  The Windows 10 refresh option did not work.  If the Windows 10 operating system fails, the  computer can not be recovered.  I returned this one and ordered another.  The replacement had the same problems.  Returned the replacement.