If that's the screen you get upon booting up (and it's a PC) then it sounds like it quit booting while in DOS mode. Try entering this command and see what happens:
cd\windows (or is it cd/windows . . . been a long time since the DOS days)
and then hit enter.
If nothing happens, you need a good service tech. If the screen changes and it says "Windows" at the prompt, try typing "windows" and hit enter again.
Brian