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What are the $NtUnstallKB* folders in my Windows folder, and can I delete them?.

In my Windows folder I have 294 folders named $NtUnstallKB******$.
Each folder has 4 to 6 files. The names of the folders and files are
all blue. There is a txt file in each folder but when I open it with
notepad it is blank.

What are these and can I safely delete them? They are taking up 1.2
Gb of disk space. My guess is they are to uninstall windows updates, to
delete them would mean I could not remove the update.

Your guess is exactly right.

Let’s look at what you’re looking at, and I’ll describe the safe
approach to dealing with this.

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If you open Windows Explorer on your Windows Directory (typically
C:\Windows), you may see the folders mentioned in our question:

$NTUninstall folders

(You will need to have “View hidden files and folders” enabled in
Windows Explorer’s options to be able to see these folders.)

“The names indicate what they are: uninstall
information for various patches and updates.”

They’re colored in Blue because the files within the folders are
compressed to save space.

The names indicate what they are: uninstall information for various
patches and updates. Most are named including a “KB number” which is
the Microsoft Knowledgebase number that describes the patch that they
are related to.

Yes, except for $hf_mig$, you can delete them. ($hf_mig$ is apparently used for coordination by future patches.) As you mention, the “cost” is that you
will no longer be able to uninstall the corresponding patch. For most
of us that’s not really a big deal. In fact, just quite coincidently, I
did exactly this earlier today on one of my machines that was running
low on disk space on it’s C: drive.

However, as you might expect, sometimes just blindly deleting things
doesn’t always end up with what you might expect. Sometimes we make
mistakes, and sometimes down the road we might wish we hadn’t deleted them.

Two suggestions for you:

  • Take a full system backup that you plan to keep prior to deleting
    the folders. In particular, this can save your bacon should you happen
    to accidentally delete something you didn’t intend to. Keep the backup
    image so that should you ever need these folders and files again you
    can recover them from the backup.

  • Copy these folders to somewhere else manually first. Perhaps copy them to
    another system, or another disk with more room, or burn them to a CD or
    DVD. Once again the goal here is to feel confident that should you need
    to replace the folders and files, you can because you kept a copy.

In general, I actually advise that you leave these folders alone
unless you have a reason to remove them. They don’t impact system
performance, and the ability to uninstall a patch has come in handy for
some folks from time to time. If you find that you’re running low on
disk space on the drive housing Windows, then yes, these are on the
list of things to consider removing.

Removing safely by copying them elsewhere first, that is.

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6 comments on “What are the $NtUnstallKB* folders in my Windows folder, and can I delete them?.”

  1. yes, leave them!
    A while ago I installed windows desktop search on my pc, which slowed it down to a crawl.
    I then used ccleaner to clean up my system and had it remove these folders.
    I wish I hadn’t…cos I couldn’t remove wds anymore.
    I finally got the folder from someone, but omg…
    So, leave those folders, or as Leo says, at least burn them onto a dvd before deleting them!!!!

    Reply
  2. well, the Windows Desktop Search has more to do with Microsoft ignoring their API’s for their software and less to do with those folders.

    Yet another gripe about Microsoft though…

    Reply
  3. I tried before to delete these folders , but every time give me an error message and can’t delete them , anyway it’s better to not delete , even these folders didn’t take so much space to delete it. thanks Leo…
    http://www.fosdir.com

    Reply
  4. Do not delete them,,save them like Leo said.
    If you need to reinstall Windows XP for some reason, and reinstall SP 2 you will find it will not install without them.
    Also SP 2 will not uninstall without them.

    Reply
  5. I’ve read in an MS KB that if you re-install a patch, then the uninstall info is recreated and you can back out a patch.

    Reply

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