Hi Big Bro, please see my replies inline.
Big Bro said:
...snip...
You were right about something changing the value. Something changed the
"Checked Value" to 3. The "Default value" was 1.
However my "Application Data" folder is hidden when the "Checked value" is
set to 1 and the "Default value" to 2, so I reversed the order and now "Show
hidden files and folders" displays correctly, when the radio button is
checked to do so. I hope there is nothing wrong with this order being
backward from your suggestion. If it is there is still something wrong.
Hmm. . . this is very interesting. Is that folder the only hidden one
that isn't shown with the value set to 1, or don't any hidden folders
show up?
The values I gave for SHOWALL, 1 for CheckedValue and 2 for
DefaultValue, are what I have in my registry and what I've found on the
web. As the CheckedValue and DefaultValue for the NOHIDDEN key (which
corresponds to the "Don't show hidden files and folders" radio button)
are both 2 (you might want to check whether they are on your system?), I
guessed that 1 means "show" and 2 means "don't show".
The registry takes the DefaultValue data if it can't for some reason
read the CheckedValue. . . so it could be that the default of 1 you set
for SHOWALL is what's actually being used. Could you -- while you have
the hidden folders visible as you want -- check this key?
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
In the right pane, look for the value called "Hidden". What is it set
to?
I would love to know what caused this problem in the first place. If there
is a setting in Tweak UI or X Setup Pro I would like to know where it is so
that I can see if either one of them is the cause.
I don't use TweakUI and don't know the other program, sorry. Not to
worry you, but there are some worms and viruses that interfere with this
setting. It could be that you have a nasty somewhere, or that you did
have and it was removed but changes it made to the registry weren't
repaired.
Well at least now I can see the hidden files and folders again, even if
those settings are backwards.
It shows we're on the right track

I think it'd be wise to do a
little more digging, though, to try to find out what's going on. I'll be
interested to know about that Hidden value
