Right out of the box Windows would not boot, fortunately a re-install from a USB drive (downloaded from Microsoft) and since Windows was activated with a digital license (tied to the motherboard) it re-activated OK. Attaching a second hard drive, however, prevents booting (it won't get past the BIOS, version A16) .  Tried several suggestions on the Dell customer support boards, none worked.  Whether SATA or USB, adding a second hard drive (at boot time) will freeze the machine.  This makes it useless when Windows decides to do an update without permission.  Avoid this machine unless you like to waste time.  Finally installed BIOS update A29 today (released by Dell a few months ago) and it still won't boot.