I have a Dell 4 in 1 desktop that I attempted to redo the windows 10 operating system.  After several days, I downloaded a win 10 recovery file

from another operating computer.  It gave me a working copy of windows 10

but will not start the system.  When I push the start button, Dell  appears and

goes no further.  Every few seconds Dell appears and disappears soon after.

when I use the F2 key, a  bios system appears and wants my Administrator

password entered which does not exist.  What can I do to fix this?