Some newer computers have what I like to call "over-sensitive BIOS's" and have been known to produce "HDD Not Found" errors when the user tried to boot the computer. Dell 9020's are the only known ones so far, but many will be sure to come.
To Resolve: Edit
1. On another computer, download the Firmware update from this link here.
2. Run the Dell_Kahuna_DEM6.exe file to a blank flash drive. NOTE: This will reformat the flash drive so make sure there is nothing important on it first.
3. Go back to the computer with error and boot to a one time boot menu (F12 on startup). Run through the GUI, it applies the update.
4. Once in Windows, verify the update was applied by running "devmgmt.msc", selecting the "Disk Drive" and go into its properties. Navigate to the "Details" tab and look for a Hardware ID ending in “DEM6”.