bloated registry

[charles96]

I recently started wondering why my registry was so large.
If I save it using regedit and export, it is currently over
60MB. I accidently discovered part of the bloat and to
confirm it, I performed the following exercise...

Open news reader and select a group. I selected this group
microsoft.public.windowsxp.help_and_support
Look for any message with a unique title. In this case I
selected a message with a time stamp of 13feb06 10:45AM and
a title "Multiple Computer Rebooting with Same Error Code".
Save a copy of that message to desktop.
Run start -> run -> regedit and search for that title.
It occurs under each of the following (hive?) keys...
HKEY_CURRENT_USER/Software/Microsoft/Windows/Current
Version/Explorer/ComDlg32/OpenSaveMRU/*/
HKEY_CURRENT_USER/Software/Microsoft/Windows/Current
Version/Explorer/ComDlg32/OpenSaveMRU/eml/
HKEY_USER/S-1.5.21.../Software/Microsoft/Windows/Current
Version/Explorer/ComDlg32/OpenSaveMRU/*/
HKEY_USER/S-1.5.21.../Software/Microsoft/Windows/Current
Version/Explorer/ComDlg32/OpenSaveMRU/eml/
(the subdirectory that begins S-1.4.21 refuses to allow itself
to be copied)
I closed regedit, deleted the file from the desktop, and
re-opened regedit and cheked. The value is still there.

I looked at a few of the adjacent keys. All sorts of things
are saved. I only recogize and remember a few. But I think
all of them are things that have been saved.
The sum total of all of them is less than 200.
So this does not explain 60MB.

Perhaps somebody else has seen this, and is aware of at
least a partial solution.
Tnx,
Charles

 

[AJR]

'I recently started wondering why my registry was so large.
If I save it using regedit and export, it is currently over
60MB. I accidently discovered part of the bloat and to
confirm it, I performed the following exercise...

Open news reader and select a group. I selected this group
microsoft.public.windowsxp.help_and_support
Look for any message with a unique title. In this case I
selected a message with a time stamp of 13feb06 10:45AM and
a title "Multiple Computer Rebooting with Same Error Code".
Save a copy of that message to desktop.
Run start -> run -> regedit and search for that title.
It occurs under each of the following (hive?) keys...
HKEY_CURRENT_USER/Software/Microsoft/Windows/Current
Version/Explorer/ComDlg32/OpenSaveMRU/*/
HKEY_CURRENT_USER/Software/Microsoft/Windows/Current
Version/Explorer/ComDlg32/OpenSaveMRU/eml/
HKEY_USER/S-1.5.21.../Software/Microsoft/Windows/Current
Version/Explorer/ComDlg32/OpenSaveMRU/*/
HKEY_USER/S-1.5.21.../Software/Microsoft/Windows/Current
Version/Explorer/ComDlg32/OpenSaveMRU/eml/
(the subdirectory that begins S-1.4.21 refuses to allow itself
to be copied)
I closed regedit, deleted the file from the desktop, and
re-opened regedit and cheked. The value is still there.

I looked at a few of the adjacent keys. All sorts of things
are saved. I only recogize and remember a few. But I think
all of them are things that have been saved.
The sum total of all of them is less than 200.
So this does not explain 60MB.

Perhaps somebody else has seen this, and is aware of at
least a partial solution.
Tnx,
Charles'

The registry is the largest file (database) on the computer - also the key
"MRU" shows the "Most Recently Used" file - it is not cleared because you
delete the file it is history until replaced by another entry. The following
refrence addresses clearing the MRU key:

support.microsoft.com/?kbid=142298

 

[Wesley Vogel]

Get MRU-Blaster
Protect your privacy - find and remove over 30,000 MRU lists!
http://www.javacoolsoftware.com/mrublaster.html

Here are a few...
Registry MRU Locations
http://windowsxp.mvps.org/RegistryMRU.htm

Here's the missing link from the OP...
How to Clear the Windows Explorer MRU Lists
http://support.microsoft.com/default.aspx?scid=kb;[LN];142298

--
Hope this helps. Let us know.

Wes
MS-MVP Windows Shell/User

In

 

[Vanguard]

I recently started wondering why my registry was so large.
If I save it using regedit and export, it is currently over
60MB. I accidently discovered part of the bloat and to
confirm it, I performed the following exercise...

Open news reader and select a group. I selected this group
microsoft.public.windowsxp.help_and_support
Look for any message with a unique title. In this case I
selected a message with a time stamp of 13feb06 10:45AM and
a title "Multiple Computer Rebooting with Same Error Code".
Save a copy of that message to desktop.
Run start -> run -> regedit and search for that title.
It occurs under each of the following (hive?) keys...
HKEY_CURRENT_USER/Software/Microsoft/Windows/Current
Version/Explorer/ComDlg32/OpenSaveMRU/*/
HKEY_CURRENT_USER/Software/Microsoft/Windows/Current
Version/Explorer/ComDlg32/OpenSaveMRU/eml/
HKEY_USER/S-1.5.21.../Software/Microsoft/Windows/Current
Version/Explorer/ComDlg32/OpenSaveMRU/*/
HKEY_USER/S-1.5.21.../Software/Microsoft/Windows/Current
Version/Explorer/ComDlg32/OpenSaveMRU/eml/
(the subdirectory that begins S-1.4.21 refuses to allow itself
to be copied)
I closed regedit, deleted the file from the desktop, and
re-opened regedit and cheked. The value is still there.

I looked at a few of the adjacent keys. All sorts of things
are saved. I only recogize and remember a few. But I think
all of them are things that have been saved.
The sum total of all of them is less than 200.
So this does not explain 60MB.

You've never heard of MRU (Most Recently Used) lists? How do you think all
those applications can list what files you opened before? Open Word and
under its File menu will be a list of your last edited documents. Open
Windows Media Player and under its File menu is an MRU. *Lots* of
applications use an MRU. This is an ease-of-use feature to let the user
restart working on a file that they were working on before in a previous
session of that application.

Configure the application, if they permit, to NOT save a history of opened
files if you fear someone seeing what is in the MRU for that application.
Not all applications provide that option. You can get cleanup utilities
that cleanout the MRUs from the registry. Most work based on known MRUs but
their database is limited to known application (in their database). For
MRUs used by unknown applications, you will need to do the cleanup yourself
although some MRU cleanup tools let you add the registry key to their MRU
list so you can use the tool later to include cleanup of those MRUs without
having to do it manually.

60MB is not that big. The MRUs are not the major contributor to the size of
the registry. The registry is NOT read from its files on the hard drive but
ONCE during Windows startup. It gets copied into memory and it is the
memory copy that gets read and updated thereafter (and then copied in the
background back to the files). Looking around through the binary tree in
the registry copy that is in memory is very fast, so a bunch of MRUs won't
slow down lookups into the registry after Windows has loaded it into memory.
Of course, it is likely that someone worried about MRUs in the registry are
trying to hide what has been recorded in those MRUs from prying eyes that
search the registry or use forensics to investigate the use of that
computer.

http://support.microsoft.com/kb/312968/en-us
http://support.microsoft.com/kb/142298/en-us
http://support.microsoft.com/kb/253171/en-us

are example articles discussing MRUs. Rather than cleaning them manually,
there are lots of privacy, security, or anti-malware tools that will do the
cleanup for you (but they only clean out the MRUs that they know about or
that you have added to their MRU list, if they allow you to add other MRU
keys).

PC Mag's ListZapper (haven't used it in a few years)
JavaCoolSoftware.com's MRU-Blaster

Or just use Google to search on "+MRU +clean"
(http://www.google.com/search?q=+MRU++clean). I don't bother cleaning
out my MRUs simply because I don't care about someone seeing them, and they
add little to the size of the registry. The time wasted to do the manually
instigated MRU cleanup far outweighs the loss in time to initially load the
registry files into memory when Windows starts up. Remember that the
registry is a big INI file where all the INI files for all applications got
rolled into the registry, and the settings stored for an application in the
registry usually far exceeds the size for its MRU list (which is usually
limited to just 10 entries).