Lost Open With with Notepad2 since moved folder

Hi all,

I have downloaded and used Notepad2 for a long time. (http://www.flos-freeware.ch/notepad2.html) Nice little software and no need for installation. You simply extract the software in a folder.

Initially Notepad2.exe was in folder C:\Notepad2\Notepad2.exe
I configured 'Open With' for .txt files to use Notepad2.exe
Everything was ok until I moved Notepad2.exe to another folder (Example: C:\Program Files\Notepad2\Notepad2.exe).

Now whenever I try to reconfigure the 'open with' of .txt files it doesn't work.
I do:
1- Right-click on .txt file
2- Choose Open With
3- Browse for Notepad2 and double click on Notepad2.exe
4- This is my problem here -> Notepad2 is not added anymore in the list <-

It seems like windows is completely lost because I moved the Notepad2.exe somewhere else.

How can I fix this?

(Note: This support page doesn't work because I already tried this and the Notepad2.exe is never added anymore to the list of 'Open with' software since I changed the folder: http://support.microsoft.com/kb/307859)