I did a stupid thing. I saw a new bio A04 came out on 5/8. I just assume my 2-week old Mini needs it. So without thinking much, I flashed it using the Windows version utility. It unpacked OK, then it was "not responsing" during the "Reading Old Bios" stage but before the"writing new Bios" stage. After 10 minutes of so, I "cancelled" the process.
My Mini 12 seemed to be working fine afterward.
Now the computer will not boot up at all. It has black screen and does not recognize any drive. I tried boot up on a DOS CD (on a USB CD drive) and nothing happened. Same with USB Flash drive.
After speaking to Dell tech support for 30 minuties, my Mini 12 is going back to Dell next week.
I am not sure what might have happened. It may be the Windows Bios flash utility is not compatible with Windows 7. May be it is something else.