Notepad2 is a light-weight, free and open source Notepad-like text editor with syntax highlighting for a few commonly used languages.It’s based on the Scintilla source code editing component and works on NT-based versions of Windows.
First you need to download notepad2 from here
First you need to Rename Notepad2.exe to notepad.exe.
Find c:\windows\notepad.exe and c:\windows\system32\notepad.exe and set the owner to ‘Administrators’, and grant Administrators full control.
Using Windows Explorer, drag and drop the renamed notepad2.exe to c:\windows and c:\windows\system32.
Optional replace the permissions on the new notepad.exe to Read & Execute and Read.