Windows 7 - Delete Backup Files of update

Asked By Mysel on 29-Apr-08 12:49 AM
Is it safe to delete backup files vista's update? Its taking a lot of space.

Bob replied on 29-Apr-08 10:54 AM
On Mon, 28 Apr 2008 21:49:00 -0700, Myself

An MVP opinion :

My personal practice is very different. These uninstall files
really take up very little room. Unless you are very short of  disk
space, I think it's safer to keep them even if you think you'll never
need them, just in case.
Ken Blake, Microsoft MVP Windows - Shell/User

Warning: One folder you should NOT delete is: $hf_mig$

It adds new entries into that folder when installing MS updates;
KB*, Q*.
MowGreen [MVP] replied on 29-Apr-08 01:12 PM
Yes, but ... you can back them up *just in case* something goes awry.
Store them on an external USB drive, thumb drive, or burn them to
portable media [CD/DVD].

I want to Save Space and delete unnecessary files after installing a
Windows Update patch or Service Pack

MowGreen  [MVP 2003-2008]
*-343-*  FDNY
Never Forgotten
Mysel replied on 01-May-08 03:08 AM
So if I delete those backup files, is it going to hamper the future updates?
I could not find any folder named "$hf_mig$" in vista. Anyway thanks for the
Mysel replied on 04-May-08 01:04 PM
So if I delete those backup files, is it going to hamper the future updates?
I could not find any folder named "$hf_mig$" in vista. Anyway thanks for the
Shenan Stanley replied on 04-May-08 02:08 PM
If you think the updates are actually using up the majority of your space -
perhaps you have too small of a hard disk drive or at least too small of a
partition for the system to be using (system being the installation and
working files of your given OS.)

Empty your Temporary Internet Files and shrink the size it stores to a
size between 64MB and 128MB..

- Open ONE copy of Internet Explorer.
- Select TOOLS -> Internet Options.
- Under the General tab in the "Temporary Internet Files" section, do the
- Click on "Delete Cookies" (click OK)
- Click on "Settings" and change the "Amount of disk space to use:" to
something between 64MB and 128MB. (It may be MUCH larger right
- Click OK.
- Click on "Delete Files" and select to "Delete all offline contents"
(the checkbox) and click OK. (If you had a LOT, this could take 2-10
minutes or more.)
- Once it is done, click OK, close Internet Explorer, re-open Internet

You can use an application that scans your system for log files and
temporary files and use that to get rid of those:

Ccleaner (Free!)

Other ways to free up space..



Those can help you visually discover where all the space is being used.

If you are concerned over less than 5GB of space total at any given time
being freed up on your hard disk drive - then something is wrong and
you would be better off spending a little and putting in a drive that is
likely 3-8 times as large as what you have not and not concerning
yourself over such a small amount of space OR you seriously need
to consider what you really need on the system and what should be

Basic housekeeping 101... - in an actual home, if your storage area gets
full - you either have to decide what you really should have in the storage
area and what could go or you have to find a new place to store stuff
that will accommodate everything you need.  You don't walk into a
warehouse of cars, look at the filing cabinet in the corner where
you keep all the records for the cars and decide that if you move it out of
the warehouse - you will have more room for cars. ;-)

Shenan Stanley
How To Ask Questions The Smart Way
sgrant replied to Shenan Stanley on 09-Mar-10 05:49 PM
Very unfortunate conclusions drawn here.  Maybe the OP has a very legitimate
reason for not wanting half a gig worth of garbage laying around on his
drive.  What happened to the good ole days of keeping our environments clean?
I want to backup my pristine machine to a DVD and trust me, the .5 gig makes
a difference.
MowGreen replied to sgrant on 09-Mar-10 06:31 PM
Which definition of garbage are you using in terms of computer science ?

1) semantic garbage
Semantic garbage is any object or data which will never be accessed
by a running program, for any combination of inputs to the program.

2) syntactic garbage
Syntactic garbage refers to objects or data within a program's
memory space that are unreachable from the program's root set.

.5 GB on modern HDs is a trivial size.
Some browsers are set by Default to cache at least that same amount.
That's the location where the malware authors are likely to stash their
executables. Yet, the Default setting of most browsers is to *retain*
said cache when the browser closes.

IF a need arises where someone *must* uninstall an update, having the
uninstall subfolders present is handy.
In the *vast majority* of cases, deleting the uninstall subfolders is
desirable since the updates will *never* be uninstalled.

Backups can be done incrementally and what is backed up should be
completely up to the User.

*Imaging* a freshly installed HD, including all apps/programs/whatever,
is another matter entirely and NO unnecessary data should ever be included.

Otherwise ... I prefer NNTP to forums as there is less garbage there. <w>

*-343-* FDNY
Never Forgotten
Harry Johnston [MVP] replied to MowGreen on 09-Mar-10 08:47 PM
Vista does not use uninstall folders, does it?  Instead it has the servicing
store, which is definitely not safe to muck about with.


Harry Johnston
MowGreen replied to Harry Johnston [MVP] on 10-Mar-10 04:54 PM
IIRC, Vista/Win7 uses VSS for branch comparison and stores the uninstall
information there. Do you know something I do not, Harry ?

*-343-* FDNY
Never Forgotten
Harry Johnston [MVP] replied to MowGreen on 10-Mar-10 09:48 PM
You may know something I do not - I have never heard that VSS may be involved.  Any

I did a bit of poking around and found this:

which more or less matches my understanding of how Vista+ servicing works.
There is also this:

and the same engineer has his own blog which is a good read if you are interested
in servicing:

In particular see the third comment on this post:

The short summary of all of this is that it is not possible to (safely) delete
the uninstallation backup files in Vista/W7, except for the special case of
service packs for which a specific tool, different for each service pack, is

It should perhaps also be specifically pointed out that these files are stored
differently than in XP.  In XP you have the system directories which contain the
current version of all the files, and you have uninstall directories which
contain backups of the files that were in the system directories at the time the
particular installation took place.  Of course, this means that unless you
uninstall updates in the right order you may wind up in an inconsistent state.

In Vista and above, the servicing store contains a copy of all the files that
were originally on your system in a single logical store (I am simplifying).  For
each update you have applied, there is another logical store containing the
corresponding files.  When you add or remove an update, the system works out
which version of each file should be in the system directories (usually the most
recent!) and puts a copy there.  (In fact, to conserve disk space, identical
files are in fact hard linked together so that there is only one physical copy.)

The upside of this is that you can add and remove updates in any order you like,
and the servicing store will make sure the right files wind up in place.  It
also eliminates some of the issues that update.exe suffered relating to the
release and hotfix branches.  it is a much more elegant system, unfortunately the
implementation does not seem to have performed as per spec.

In principle I suppose someone could reverse engineer the servicing store and
figure out how to identify those files that have been superceded, and then
delete them.  On the other hand, I suspect that Windows would notice they were
missing, mark the servicing store as corrupt, and refuse to install any further
updates until the problem is corrected.

MowGreen replied to Harry Johnston [MVP] on 11-Mar-10 05:07 PM
Have already seen those 2 blog articles explaining CBS and WinSxS
before, but I cannot find their relation to VSS anywhere ... yet. <w>
Since my XP HD up and died, I no longer have the reference handy. Will
ask and get back to you.

Wouldn't it be neat if MS actually included all of the info on TechNet
so that we did not have to rummage around the 'net trying to scruff it up
... or is that asking too much ?

*-343-* FDNY
Never Forgotten
Harry Johnston [MVP] replied to MowGreen on 11-Mar-10 07:07 PM
About half the time I eventually find the information I needed was on TechNet or
MSDN after all, but I usually only find it completely by accident while
researching something else months later.

I think perhaps the index and the search engine could do with a little work!


Harry Johnston
Robert Aldwinckle replied to Harry Johnston [MVP] on 12-Mar-10 01:10 PM
The problem is  Okapi.   If you want to search for more than one term you
*must* separate them with  AND  (all caps).    Even worse is not having
closures any more.   E.g. in order to search for  KBWU*  you have to express
it like this:    KBWUA THRU KBWUZ   (really intuitive that! and hopefully it
does not overlook any other non-alphabetic possibilities outside that range.)
However, I recently read somebody asking about  Document Explorer version
9.0?   I have not been doing any offline browsing for a long time.   Perhaps
it has all changed?   Maybe even back to the way it *used* to work?   <eg>

MowGreen replied to Harry Johnston [MVP] on 13-Mar-10 04:19 PM
After further rummaging I found another blog, by an MVP, that confirms
what I did NOT know about WinSxS:,-Vista-and-Server-20032008.html

and, another on MSDN about why one should keep their mitts off it:
Deleting from the WinSxS directory

The only info I found on VSS dealt with XP/WS2K3 and further confused
me, which is not really that hard to do.

In conclusion, I am starting to think that certain security software is
the culprit behind missing/corrupt .mum and manifest files that are
supposed to be hard linked to the registry (0x800F0900, 0x80070002, etc)
Such errors are supposed to/may be rectified when running CheckSUR.
That explains why the size of the January release of CheckSUR for Vista
x86 is 104.1 MB as compared to the one for Win 7, which is "only"
28.9 MB.

Thanks for putting me onto this information, Harry.

*-343-* FDNY
Never Forgotten