Disk Cleanup’s new feature called Windows Update Cleanup is standard in Windows 8 and Windows 8.1 and was added to Windows 7 by an update that was made
available in October 2013. The Windows Update Cleanup
feature is designed to help you to regain valuable hard disk space by removing
bits and pieces of old Windows updates that are no longer needed.

I’ll take a closer look at the Disk Cleanup
tool and then focus on the new Windows Update Cleanup feature. As I do, I’ll
give you a little background on the Windows update leftovers that this tool is
designed to eliminate.

Note: Disk Cleanup and the Windows Update Cleanup feature works the same
in Windows 7, Windows 8, and Windows 8.1. This article applies to all
of those Windows versions, though all of the example screen shots are from a Windows
8 system.

The WinSxS folder

If you used the Windows operating system back in the Windows
9x days, you’re familiar with the term DLL Hell. This situation arose when you installed different
programs that included updated versions of Dynamic Link Library (DLL) files
with the same name as files already on the system. These duplicate files would
wreak havoc with applications and the operating system. For example, an
application would look for a specific version of a DLL file, but find a newer version
that was recently updated by another program. Since the version was different,
the application would act strangely or crash altogether.

By the time Windows Vista was introduced, Microsoft solved the problem by creating a new technology called componentization, which
uses a folder called the WinSxS folder that allows the operating system to store
and keep track of all kinds of operating system files (DLLs included) with the
same name but different versions. WinSxS is short for Windows Side-by-Side and refers to using files with the same name
but with different version numbers at the same time in the operating system.

As things evolved, the WinSxS folder also became the perfect
place to store files added to the operating system by Windows Update. Microsoft releases a multitude of
updates every month to keep up with bugs, new applications, and security
problems (just to name a few of the reasons for the regular updates). In order to
make sure the updates don’t cause compatibility problems, all kinds of
duplicate files get stored in the WinSxS folder so that everything can continue
to function correctly. Furthermore, many Windows updates are designed such that
if they do cause unanticipated compatibility problems, they can be uninstalled, and the files can be reverted back to a previous state.

While this is a pretty simplified description of the WinSxS
folder, the general idea I want to convey is the WinSxS folder
can grow so large that it takes up a good chunk of hard disk space. The problem
gets compounded by the fact that, because the WinSxS folder is used to store so
many files, really old files or files that are no longer necessary can still
be taking up hard disk space.

For instance, Figure A shows the WinSxS folder on a system
that began as a Windows 7 system and then upgraded to Windows 8. The WinSxS folder on this system contains 58,739 files and takes up 6.89 GB of hard disk space. (In comparison, one of my
Windows 7 systems has 54,524 files and is using up 11.1 GB of hard disk
space.)

Figure A

The WinSxS folder can be quite
large. (Click to view a larger version of the image.)

If you want more technical detail about the origin of componentization
and the WinSxS folder, you can read this 2008 post from the Ask the Core Team blog on the Microsoft TechNet site.

The Disk Cleanup tool

The Disk Cleanup tool has been around for quite
some time and is designed to allow you to easily clean out old and unnecessary
files that can clog up your hard disk; it’s the perfect place for
Microsoft to add the new Windows Update Cleanup feature, which is designed to
weed through the WinSxS folder and eliminate waste. Rather than just jumping straight into the Windows Update
Cleanup feature, let’s take a closer look at the Disk Cleanup tool as a whole
and then delve into the new feature.

To launch the Disk Cleanup tool, access the Start
Menu or the Start Screen and type Disk Cleanup. Once you launch Disk Cleanup,
if you have more than one hard disk in your system, you’ll be prompted to
select drive C. Disk Cleanup will begin to analyze the files on your hard
disk to determine what can be safely removed (Figure B).

Figure B

When you launch the Disk Cleanup tool, it will calculate how much space you’ll be able to free up.

Once the disk space analysis is complete, you’ll see the
main Disk Cleanup interface (Figure C), which essentially contains a
list of all the categories or locations containing unnecessary files on your
hard disk that can be removed. Adjacent to each category you’ll see the size of
the unnecessary files as well as a check box that allows you to specify that
you want to remove those files. Beneath the list is a number indicating the
total amount of disk space that you’ll gain by removing the selected files.
Immediately below the list is the description panel, which will provide you with more
details about the category that is currently selected. The
categories you see in the list will depend on what the Disk Cleanup tool
found on your hard disk. 

Figure C

The main feature of the Disk
Cleanup interface is the Files To Delete scrolling list.

Table A: The most common categories listed in the Disk Cleanup
tool.

Category Description
Download Program Files

Downloaded Program Files are ActiveX controls and Java
applets downloaded automatically from the Internet with you view certain pages.
They are temporarily stored in the Downloaded Program Files folder on your hard
disk.

Temporary Internet Files

The Temporary Internet Files folder contains webpages
stored on your hard disk for quick viewing. Your personalized settings for
webpages will be left intact.

Offline webpages

Offline pages are webpages that are stored on your
computer so you can view them without being connected to the Internet. If you
delete these pages now, you can still view your favorites offline later by
synchronizing then. Your personalized settings for webpages will be left
intact.

Game News Files

(Windows 7 only)

The Game News Files facilitate delivery of RSS
feeds to your Game Library.

Game Statistics Files

(Windows 7 only)

The Game Statistics Files are created to aid
maintenance of various game statistics.

Debug Dump Files

Files created by Windows.

Recycle Bin

The Recycle Bin contains files you have deleted from your
computer. 

Setup Log files

Files created by Windows.
System error memory dump files Remove system error memory dump files.
System error minidump files Remove system error minidump files.

Temporary files

Programs sometimes stores temporary information in
the TEMP folder. Before a program closes, it usually deleted this information.
You can safely delete temporary files that have not been modified in over a
week.

Thumbnails

Windows keeps a copy of all your picture, video,
and document thumbnails so they can be displayed quickly when you open a
folder. If you delete these thumbnails, they will be automatically recreated as
needed.

User file history

Windows stores file versions temporarily on this
disk before copying them to the designated File History disk. If you delete
these files, you will lose some file history.

Per user archived Windows Error Report

Files used for error reporting and solution checking.

Per user queued Windows Error Report

Files used for error reporting and solution
checking.

System archived Windows Error Report

Files used for error reporting and solution
checking.
System queued Windows Error Report Files used for error reporting and solution
checking.

As you select the various categories in the list, a View
Files button may appear. If it does, you can click it to launch a separate
Windows/File Explorer window targeted on the location and showing you all the
unnecessary files stored there. Keep in mind that the View Files button is not
available for all of the categories.

The Windows Update Cleanup feature

If you refer back to Figure C, you’ll see that adjacent to
the View Files button is a button titled Clean Up System Files. You’ll
notice this button is flagged with the User Account Control (UAC) icon.
Depending on your UAC setting, you may see a UAC prompt when you select that
button. The Clean Up System Files button provides you with
access to the Windows Update Cleanup feature.

When you select the Clean Up System Files button, Disk
Cleanup will again display the screen shown in Figure B as it analyzes
additional locations on your hard disk to determine what can be safely removed.
When the main Disk Cleanup interface returns, you’ll find that a new category
called Windows Update Cleanup appears in the list (Figure D). In
addition, you may find several other new categories. 

Figure D

Windows Update Cleanup appears
in the Disk Cleanup list.

Table B: Categories that appear in Disk Cleanup when you select
the Clean up system files button.

Category Description
Windows Update Cleanup

Windows keeps copies of all
installed updates from Windows Update, even after installing newer versions of
updates that are no longer needed and taking up space. (You might need to
restart your computer.)

Device driver packages

Windows keeps copies of all
previously installed device driver packages from Windows Update and other
sources even after installing newer versions of drivers. This task will remove
older versions of drivers that are no longer needed. The most current version
of each driver package will be kept.
Windows Defender Non critical files used by
Windows Defender
Windows upgrade log files Windows upgrade log files
contain information that can help identify and troubleshoot problems that occur
during Windows installation, upgrade, or servicing. Deleting these files can
make it difficult to troubleshoot installation issues.
Service Pack Backup Files Windows saves old versions
of files that have been updated by a service pack. If you delete the files, you
won’t be able to uninstall the service pack later.

Windows Update Cleanup only
appears in the list when the Disk Cleanup wizard detects Windows updates that
you don’t need on your system. For example, when I ran Disk Cleanup’s Windows
Update Cleanup feature on a Windows 8.1 system that had recently been updated
from Windows 8 to 8.1, the Windows Update Cleanup category did not appear in
Disk Cleanup because everything had recently been cleaned up by the Windows 8.1
update.

When you click OK, Disk Cleanup will prompt you to confirm
that you want to permanently delete the selected files (
Figure E).

Figure E

Disk Cleanup will prompt you to
confirm the permanent delete operation.

Disk Cleanup will then go to work cleaning up all the files
in the categories that you selected, including the Windows Update files (Figure F).

Figure F

Disk Cleanup will remove any
unnecessary Windows Update files.

The end result

You’ll want to restart your system once Disk Cleanup
completes its operation. When your system restarts, any unnecessary Windows
Update files will be completely removed. As you survey the results, keep in
mind that the Windows Update Cleanup feature will only remove files that it
finds are no longer needed by the system, so you may find that a lot of
files have been removed from your system or you may find that very few files
have been removed from your system.

For example, after running the Windows Update Cleanup
feature on my Windows 8 system, the number of files only dropped from 58,739 to
58,130 and the size of the WinSxS folder only dropped from 6.89 GB to 6.83 GB — a very small gain. However, on my Windows 7 system, the number of files dropped
from 54,524 to 47,454, and the size of the WinSxS folder dropped from 11.1 GB to
7.86 GB — a modest gain of 3.24 GB of hard disk space.

What’s your take?

Have you used
Disk Cleanup’s new Windows Update Cleanup feature in Windows 7 or 8.x? If so,
what kind of disk savings did you encounter?

If you have comments or
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