Man, I wish I had known about this C++ coded Notepad alternative a long time ago. This text editor is just awesome, I haven't used a text editor this awesome since Emacs. Besides being just a notepad-style text editor, it is also a powerful developing tool. It supports color coding and auto-complete for a wide variety of programming languages, and it also supports a wide variety of human languages. I love the tabbed document layout, and I especially love the fact that you can close it and when you reopen it, all your documents that you were working on are right there just as you left it (assuming you saved them of course.) Besides that, Notepad++ has a powerful search feature, the ability to record and run macros, the ability to launch your code in a variety of browsers, and to add plugins to increase your productivity.
Best of all, Notepad++ is open source software published under the GPL- it's free as in "speech" and free as in "beer". So if you are looking for a great free Notepad alternative, or an Emacs alternative for Windows, go grab Notepad++ today. Consider making a donation if you like it, the author(s) put a lot of work into this.