I also use Norton Commander even up to now on Windows 7 Ultimate 64-bit. It works with a mouse too even if runs like a DOS program. The NC version is 2.01.000, copyright 1995-1999. The total footprint is only 2.47MB. When running, the NC.EXE takes up only 3.1MB of RAM.
It helps me quickly get inside hidden folders and also see hidden files without changing the View settings on Windows Explorer. I’ve never had problems with it. I think the only time I’ll leave this antique is when it would no longer run on Windows.