Hi-I bought a used Dell OPTIPLEX 780 with no o/s installed to replace my old Dell Dimension 3000.  I have a brand new copy of Windows 7 to install on it.  I've reinstalled xp on my old computer 2 or 3 times so I'm not completely new to this but, I thought I'd try to find out as much as possible before I begin.  Any advice will be appreciated.  I am wondering - when I connect the keyboard, MOUSE and monitor to the Optiplex with no o/s, will it recognize the components so that I can begin the installation of Windows 7?YesThank you very much! I was thinking that you MAY have a problem USING a USB mouse or keyboard on a fresh OS install but the 780 was manufactured in 2010-2011 so you should not have a problem with this issue. I have very much confidence in Allan's guidance with all the help he's given to me, but I'm just thinking if you have an issue, and have a PS2 mouse - keyboard around, maybe you could try that before investing more. (the 780 has both PS2 PORTS available)
 (Certainly no distrust in Allans judgement here at all, this is just a memory of mine about your same issue that I had with an older PC a few years ago).
Have fun, and good luck!
Mike