Now that you're convinced, let's get Notepad++ up and running. If you aren't convinced or want to use some other software to code with, that's fine. Just skip to the next section.
Navigate your web browser to http://notepad-plus-plus.org. Click on the Download tab on the page.
Click the link to Download Current Version.
Click the link that ends with Installer.exe.
When your download is finished run the file and you'll see this screen pop up:
Click Next to get the installation started and accept the terms. You'll be prompted again about where you want to install.
Again, the default directory is just fine. Click Next and you'll find yourself prompted once more, this time about the components you want to install.
The default configuration contains everything you'll need, so just click Install. When it's done go ahead and open Notepad++ so it can update itself if necessary.