I proudly present the 10001:th entry about notepad replacements in windows!
My favorite is metapad - it might not be the fastest or the lightest nor does it have all the super cool features - But it is a good compromise of all categories. Try it!
To replace it in windows vista, I found a good guide on simonguest.com's blog. Here's a quick recap:
Start a cmd prompt as admin and write:
1: takeown /f {path_to_notepad}\notepad.exe
then
2: cacls {path_to_notepad}\notepad.exe /G {username}:F
for both c:\windows\system32\ and c:\windows\ because notepad.exe is located in both (as simonguest forgot to mension)
3: rename metapad.exe to notepad.exe and copy+replace to both locations (start with system32\)
Go download metapad from the coolest url ever: liquidninja.com!