Well, adding to the thread, I didn't trust any either. So I decided, as a
developer, to start doing a safe one, not necessarily a complete or
efficient one, just a safe one. One that could get rid of data that wasn't
needed. Here was I discovered, while cross-referencing my program with
MS-PSDK, DDK and other tools (like Norton Windoc and Spybot S&D):
* There are two kinds of people. Nice people and morons.
* Morons can be employed as a small sprocket in a large, nice, stable
program. Thus something that works like a charm for ages breaks if you
sneeze at the right time.
* People abuse registry. This is the reason why I don't store things in
the registry unless I need it there, otherwise I uses INI files and
proprietary formats.
* Each tool has a different understanding of the registry. Each time I
scanned with each program I found different opinions, keys that were valid
but listed as errors, keys that I added in error and did not show up.
As a result:
* An Application key, where programs should store <exename>=<path> so you
can run <exename> from anywhere, can be found in the for of <My
company>=<Yourapp.exe>. This is a copy/paste, not an example.
* Applications store GUID implementation in the same key as GUID
declaration, thus obtaining a loop.
* Applications adds themselves to all menus by adding a key to each
extension.
You can't clean monsters like that. Because you expect things to be The
Right Way (tm). Now imagine you apply a clean algorythm to such keys.
In the first example, you try to see if the application is actually there.
Imagine some moron stores "%1" in there because he does not understand that
he/she can't use vars in the registry like that. You end up deleting the
first program on the disk.
In the second example, you try to locate the implementation key. Delete
it. Now jump to declaration. Error. You delete the wrong key.
Third example. Uninstall, the moron removes, you clean up, you lose all
associations, can't run programs, reinstall.
People store pathless executables to the registry because "they know where
it is" or because "it isn't used". It's not used unless a cleanup program
scans the key.
Things are quite complex, you can't just blindly clean. How many times on
this and other groups you found topics like "Can't view thumbnails any more
in W2k" or "my thumbs appear as small icons" or "Can't access propery page
for...". All these are registered handlers some program modified and, when
uninstalled, did not restore. Keys that should not be cleaned up.
You can clean up MRU lists, Explorer temporary settings, etc. But what
good is a registry cleanup that frees 40k?
A cleanup program is working perfectly on a fresh machine. When you start
adding misc. programs, you start adding errors, REGARDLESS OF PROGRAM. Don't
think MS is bug-proof, neither is Symantec, or <insert-your-trusted-source>.
Smart, "hackish" ways of doing things will put any cleanup program to risk.
Oh and as for my cleanup program... It ended up as a registry consistency
checker. It featured so many validity checks, I decided to add fixes to the
errors instead of cleanup. It does 11 passes and -believe it or not- it
finds on average 1-2 errors a day, even though it's by far not a complete
program. After 1.5 years with this installation, registry is 24 MB.
