If you are like me you need to change the default text document application on Windows. I used to change it to Wordpad but nowadays I choose Notepad++. Notepad++ is an excellent notepad replacement. All you need to do to switch out Notepad with Notepad++ is to right click on a TXT document and choose open with. If you do not see the option hold down the ALT key as you right click. Then select Notepad++ as the application. You will have to browse to it. If it is installed in the default location it will be in C:\Windows\Program Files\Notepad++. You will check the check box to make this the default application.
Just repeat for any other file type you want to open with Notepad++ default. This will also work for changing pretty much the default application for any file type as well. Enjoy!