Thanks Rick (aka Nutcase) for your reply.
I should have also posted this clarifications:
When I go to the Windows directory and double click on
notepad.exe, it does open successfully. Also if I go to
Start --> Run and type notepad, it does in fact launch
notepad. It also starts when I go to Start-->Program
Files-->Accessories-->Notepad. So, it doesn't look like
notepad itself is corrupted.
As I explained in my initial post, I tried to rebuild the
association, but that did not work. When the "Open With"
dialog box appears, it has another program selected
already. I'll call this program XYZ fo discussion
purposes. I've tried 2 different things:
1) I've changed the highligh to "Recommended Programs:"
and then hit the browse button. I locate the notepad
executable (C:\Wondows\notepad.exe) and click ok. It
takes me back to the "Open With" dialog box. "Recommended
Programs" is still highlighted (only now in light grey
highlight). There are no new choices in the list to pick
from. Hence Notepad has not been added to the list. And
the OK button is dimmed out unless I select a program from
the existing list. So, Notepad is not a choice I can
select and I can go no further.
2) This is very similar to 1) above, except I leave the
highlight on the program that is already selected when I
first open the "Open With" dialog box. Again, I'll call
this highlighted program XYZ. I then hit the browse
button. Find notepad as I did in 1) above. When I'm
taken back to the "Open With" dialog box, the previously
selected program, XYZ, is still highlighted (only now in
light grey highlight). There still is no Notepad choice
added. If I just go ahead and click the OK button, the
file attempts to open with program XYZ (but it fails,
since the program doesn't recognize the TXT file type).
So, using the Browse button to locate the notepad
executable seem to have no affect. I assume this is a bug.
Oddly enough, I just noticed that when I run hijackthis
and generate a startupList log, it contains this entry:
File association entry for .TXT:
HKEY_CLASSES_ROOT\txtfile\shell\open\command
(Default) = %SystemRoot%\system32\NOTEPAD.EXE %1
I would have thought "Default" would have been set to
nothing (given that when I go to Windows Explorer -->
Tools --> Folder Options --> File Types, and look for TXT,
the "Open With" specification is blank.).
But what is more interesting is that the path is not
correct. Notepad.exe does not live in the system32
subdirectory. It is in the c:\Windows directory itself
(which is what I assume %SystemRoot% is set to).
So, why did the installation of SP2 change this, and how
do I fix this safely?
Thanks,
Rich