Notepad++ not launching in Windows 7

Try removing any residual files that it can leave behind. I'm not familiar with the portableapps version but the normal install will store files in %appdata%\Notepad++. (You can type %appdata% in the run box to get there, if you want to go by hand it's C:\Users\username\AppData\Roaming). Delete the Notepad++ directory there and try launching it again.

This method worked for me: