Notepad and Notepad2 are simple text editors. They don't have an underline function.
WordPad is included with Windows. If you want to create a document and underline text, you can do so in WordPad. You can find from the Start Menu/All Programs/Accessories.
WordPad also has the ability for bold, italics, and changing text color.
Edited by Queen-Evie, 08 July 2011 - 12:37 PM.