Copy EVERYTHING
When I was actively working in IT and was upgrading someone's PC, I copied EVERYTHING from the old PC to the new one, into a directory called C:\OLDPC. I then went thru the directories, deleting what I knew WASN'T needed (like Windows executables, etc.). Some people put files in the strangest places. I had a boss who fancied herself a power user (and she COULD do great things with graphics programs like PowerPoint) but was hopeless when it came to understanding the OS, directory trees, etc. When I did one upgrade for her, I found PowerPoint presentations in C:\MOUSE! Better to copy everything and then cull than take a risk of losing something important, IMHO.
