I often end up with a lot of duplicate windows, it would be nice to have an utility to close them, leaving just one of a kind. Or it could put an opened instance forward should I try to access open one more. For example, I could wind up with five "c:\foo\bar" open, I only need one, the extra five just take up screen real estate and create clutter in the task bar.
I don't think you're going to find a utility or settings that will allow Explorer to work as you'd like.
My suggestion is to get yourself a tabbed browser add-on for Explorer, that way you only have one window, with a bunch of tabs. Personally I use QTTabBar:
It adds quite a few other useful features you may want to check out as well (ie: Folder expansion on hover, etc.).
Check out these SU questions for more suggestions on tabbed browser add-ons:
If you just want to outright replace Explorer with one that perhaps has your functionality requirements, here's a question with some ideas: