Cleaning Up After Updates: Reclaiming Gigabytes From WinSxS

3 Aug 2026

Windows Update keeps your computer secure, but months of cumulative updates, feature changes and replaced system components can leave the system drive with considerably less free space.

When users investigate, one folder often appears to be responsible:

C:\Windows\WinSxS

WinSxS is the Windows component store. It contains the components Windows needs to install updates, enable optional features, repair system corruption, recover from certain failures and uninstall problematic updates. It is not an ordinary cache folder, and its contents must never be deleted manually.

Fortunately, Windows includes safe tools for analysing and cleaning the component store. Used correctly, they can remove superseded update components and recover useful storage without damaging the operating system.

The important distinction is:

Clean WinSxS using Windows servicing tools—never through File Explorer, a third-party cleaner or a manual deletion script.

Why WinSxS Appears So Large

Right-clicking the WinSxS folder and selecting Properties can produce an alarming figure. However, File Explorer does not provide an accurate picture of how much unique storage the folder consumes.

Windows uses hard links, which allow several file paths to refer to the same physical data on the drive. A Windows system file may appear inside WinSxS and elsewhere under the Windows directory, but that does not necessarily mean two complete copies occupy twice the space. File Explorer can count both references when calculating a folder’s apparent size.

This means a folder that appears to occupy 15GB does not necessarily represent 15GB of removable overhead.

Some of that space consists of:

Files actively used by Windows
Components shared with other Windows locations
Optional-feature files
Component-store metadata
Previous component versions retained for recovery
Superseded packages that can genuinely be removed
Temporary servicing information

You should therefore analyse the component store before deciding that it needs cleaning.

What WinSxS Is Used For

The Windows component store supports several important functions:

Installing Windows updates
Enabling or disabling optional features
Repairing damaged system components
Changing Windows editions
Recovering from some boot or corruption problems
Removing supported problematic updates
Providing side-by-side component versions required by applications

Windows Update and DISM both rely on packages and components maintained through the component store. Removing individual files can break the relationship between Windows, its servicing database and the installed operating-system files.

Microsoft warns that manually deleting files from WinSxS can make the PC unbootable and prevent future Windows updates from installing.

Before You Begin

Before performing system-level cleanup:

Install any pending Windows updates.
Restart the computer.
Return to Windows Update and confirm that another restart is not pending.
Back up important files.
Save the BitLocker recovery key.
Close business applications.
Connect a laptop to mains power.
Check the current free space on the system drive.
Record the current Windows build using winver.

Do not perform aggressive cleanup immediately after an update if you have not yet confirmed that Windows, your applications and your hardware are operating normally.

Retaining some previous components gives Windows the opportunity to recover or roll back when a new component causes trouble. Windows normally keeps previous versions for a period before automatically removing them.

Step One: Check How Much Space Is Actually Reclaimable

Open Terminal, Command Prompt or PowerShell as administrator.

Run:

Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore

This command does not remove anything. It creates a report showing how the component store is being used.

A typical result includes:

Windows Explorer Reported Size of Component Store

Actual Size of Component Store

Shared with Windows

Backups and Disabled Features

Cache and Temporary Data

Date of Last Cleanup

Number of Reclaimable Packages

Component Store Cleanup Recommended

Windows Explorer Reported Size

This is the figure File Explorer may effectively report. It does not properly account for WinSxS hard links and can therefore make the directory look larger than its unique physical footprint.

Actual Size of Component Store

This measurement accounts for hard links more accurately, although it still includes components shared with the active Windows installation.

Shared With Windows

These files are used by Windows through hard links. They should not be viewed as unnecessary WinSxS overhead because the operating system still requires them.

Backups and Disabled Features

This includes older components retained for recovery, component metadata and files associated with optional Windows features.

Some of this storage may become reclaimable, but not all of it is unnecessary.

Cache and Temporary Data

This includes information used internally to make Windows servicing operations more efficient.

Number of Reclaimable Packages

This shows how many superseded packages component cleanup may be able to remove.

Component Store Cleanup Recommended

This is the most useful summary.

If it says:

Component Store Cleanup Recommended : Yes

a cleanup may recover worthwhile space.

If it says:

Component Store Cleanup Recommended : No

Windows does not currently expect the standard component cleanup to produce a meaningful reduction.

Step Two: Start With Storage Settings

Before using advanced commands, open:

Settings > System > Storage

Review:

Temporary files
Cleanup recommendations
Recycle Bin
Downloads
Delivery Optimisation files
Previous Windows installations
Large or unused applications

Microsoft recommends Storage Sense and Cleanup recommendations as the normal first methods for freeing storage required by Windows and Windows Update.

Select only categories you understand.

Pay particular attention to whether the list includes:

Windows Update Cleanup
Temporary Windows installation files
Previous Windows installation
Device-driver packages
Delivery Optimisation files

The categories available depend on what Windows currently has stored.

Be Careful With Downloads

Storage Sense does not delete Downloads using its default settings, but it can be configured to do so. Check the chosen settings before running an automatic cleanup.

Be Careful With Previous Windows Installation

After a feature upgrade, Windows may retain the previous installation under:

C:\Windows.old

Deleting it can recover a substantial amount of space, but it also removes the ordinary Go back option for returning to the previous Windows version. Microsoft normally removes the previous installation automatically after ten days.

Only remove it early when:

The upgrade has been fully tested.
Your files and applications are present.
Drivers and business systems work.
You are confident that you will not need to return to the earlier Windows release.

Windows.old and WinSxS are separate. Deleting the previous installation does not constitute a WinSxS component cleanup.

Step Three: Use Disk Cleanup for System Files

The older Disk Cleanup utility remains useful for Windows system cleanup.

Search Start for:

Disk Cleanup

Then:

Open Disk Cleanup.
Select the Windows drive, normally C:.
Select Clean up system files.
Select the Windows drive again.
Wait while Windows recalculates the available categories.
Review the items carefully.
Select the categories you want to remove.
Select OK.
Confirm Delete Files.

The Windows Update Cleanup option removes update-related files that Windows no longer requires and can reduce component-store overhead. Disk Cleanup can also remove temporary system files and other unnecessary data.

Do not select every category automatically. Review whether it includes:

Previous Windows installations
Downloads
Device-driver packages
Temporary setup files
Error-reporting information you may still need for troubleshooting

Step Four: Run the Standard DISM Component Cleanup

If DISM reports reclaimable packages or recommends cleanup, open an elevated terminal and run:

Dism.exe /Online /Cleanup-Image /StartComponentCleanup

This removes superseded versions of Windows components that have been replaced by newer versions. It performs a similar function to Windows’ automatic StartComponentCleanup maintenance task, but it removes eligible older versions immediately rather than waiting through the normal grace period. It also does not have the scheduled task’s one-hour execution limit.

The operation may take some time.

While it runs:

Keep the computer connected to power.
Do not force a shutdown.
Do not close the terminal simply because progress appears slow.
Avoid beginning another Windows servicing operation.
Allow it to report whether it completed successfully.

When it finishes, restart Windows.

Then rerun:

Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore

Compare:

Actual component-store size
Backups and disabled features
Reclaimable packages
Cleanup recommendation
Free space on the Windows drive

The recovered storage varies. On some systems, the difference may be small because Windows has already performed automatic maintenance. On others—particularly systems that have received many updates without completing maintenance—the reduction can be more noticeable.

Windows Already Performs Automatic Cleanup

Windows includes a scheduled task called:

\Microsoft\Windows\Servicing\StartComponentCleanup

When it runs automatically, it waits at least 30 days after a component is updated before removing the previous version. This grace period preserves a recovery window in case the newer component causes problems. The scheduled task also has a one-hour timeout.

You can run it manually through Task Scheduler:

Open Task Scheduler.
Go to:

Task Scheduler Library

> Microsoft

> Windows

> Servicing

Select StartComponentCleanup.
Select Run.

Alternatively, run:

schtasks.exe /Run /TN "\Microsoft\Windows\Servicing\StartComponentCleanup"

This is a supported alternative to the DISM command, although the manually started scheduled task can still be limited by its normal execution behaviour.

You do not normally need to run this task every week. Windows is designed to maintain the component store automatically when normal maintenance has enough opportunity to complete.

What

/ResetBase

Does

You may see this more aggressive command recommended online:

Dism.exe /Online /Cleanup-Image /StartComponentCleanup /ResetBase

The /ResetBase option removes all superseded versions of every component in the component store. This can provide additional cleanup beyond ordinary StartComponentCleanup.

However, it has an important consequence:

After /ResetBase completes, all update packages that existed at that point can no longer be uninstalled.

Future update packages are not permanently blocked from being uninstalled, but the current servicing state becomes the new base.

Use

/ResetBase

Only When:

Windows is operating correctly.
All recent updates have been tested.
The computer has been restarted successfully.
Critical applications and hardware work.
A verified backup exists.
The BitLocker recovery key is available.
You accept that the currently installed update packages cannot be removed individually.
The extra storage is genuinely necessary.

Do Not Use

/ResetBase

When:

A recent update may be causing problems.
Windows is crashing or unstable.
An update rollback is being considered.
The PC has pending updates or restarts.
You have not verified your backup.
The device is a business-critical system awaiting update validation.
You are running it simply as routine weekly maintenance.

For most users, the normal command is preferable:

Dism.exe /Online /Cleanup-Image /StartComponentCleanup

Treat /ResetBase as an intentional servicing decision—not a harmless “deep clean” button.

Cleanup Is Not the Same as Repair

These DISM options have different purposes.

Analyse the Store

Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore

Reports component-store size and reclaimable packages.

Clean Superseded Components

Dism.exe /Online /Cleanup-Image /StartComponentCleanup

Removes eligible replaced component versions.

Establish a New Permanent Base

Dism.exe /Online /Cleanup-Image /StartComponentCleanup /ResetBase

Removes superseded versions and prevents existing update packages from being uninstalled.

Check for Corruption

Dism.exe /Online /Cleanup-Image /CheckHealth

Checks whether the image has already been marked as corrupted.

Scan for Corruption

Dism.exe /Online /Cleanup-Image /ScanHealth

Performs a deeper component-store corruption scan.

Repair Corruption

Dism.exe /Online /Cleanup-Image /RestoreHealth

Scans the Windows image and attempts to repair damaged components.

RestoreHealth is not intended to reclaim storage. In some situations, repairing Windows may temporarily require additional files and space.

Do not run a long chain of DISM commands without understanding why each one is needed.

What to Do if Component Cleanup Fails

A failed component cleanup can indicate:

Pending update operations
A restart that has not completed
Component-store corruption
A damaged servicing package
Insufficient free space
A Windows service problem
Storage errors
A wider Windows Update failure

Begin with the least disruptive steps.

1. Restart Windows

Select:

Start > Power > Restart

After the restart, allow Windows to settle and check Windows Update again.

2. Finish Pending Updates

Open:

Settings > Windows Update

Install available updates and complete every requested restart.

3. Analyse Again

Run:

Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore

Confirm whether cleanup remains recommended.

4. Check Component-Store Health

Run:

Dism.exe /Online /Cleanup-Image /ScanHealth

If corruption is found, run:

Dism.exe /Online /Cleanup-Image /RestoreHealth

DISM can repair the local Windows image by checking component-store files, manifests and component-servicing configuration.

5. Run System File Checker

After DISM completes successfully, run:

sfc /scannow

Restart after the scan.

6. Check Storage Health

When cleanup repeatedly fails alongside:

File corruption
Windows Update failures
Freezing
Disk errors
Unexpected restarts

check the SSD or hard drive before performing increasingly aggressive servicing operations.

A failing drive should be backed up and replaced rather than repeatedly cleaned.

Why Cleanup May Recover Less Than Expected

You may run StartComponentCleanup successfully and recover only a small amount of space.

Possible reasons include:

Windows already completed automatic cleanup.
Most of the apparent WinSxS size consists of shared hard-linked files.
Few packages have been superseded.
Previous components are still within their retention period.
The files belong to currently enabled or available Windows features.
The true component-store overhead was already small.

DISM’s report is more meaningful than the folder’s Properties window.

Microsoft’s own example shows a component store reported by Explorer as nearly 5GB while the actual removable overhead was only about 507MB.

A successful cleanup should therefore be judged by:

Free drive space before and after
Number of reclaimable packages
Actual component-store size
Backup and cache overhead
Whether cleanup remains recommended

Do not expect the full apparent WinSxS folder size to become free space.

Other Places Updates Consume Storage

WinSxS may not be the main reason the system drive is full.

Also review:

Windows.old

The previous Windows installation retained after a feature upgrade.

Temporary Installation Files

Files used to prepare or complete a Windows installation.

Delivery Optimisation Files

Locally cached update content used by Windows delivery services.

Update Downloads

Packages downloaded before installation.

Restore Points and Shadow Copies

Recovery information can consume significant storage depending on the configured limit.

Memory Dumps

Blue-screen and crash dumps may range from small diagnostic files to several gigabytes.

Hibernation File

hiberfil.sys supports hibernation and parts of Windows power management.

Page File

pagefile.sys supports virtual memory and system commit requirements.

User Profiles

Downloads, Desktop files, browser caches, Outlook data and application caches may consume more space than Windows servicing.

Do not focus exclusively on WinSxS because its name appears unfamiliar.

What You Must Never Delete Manually

Never manually delete or take ownership of:

C:\Windows\WinSxS

C:\Windows\servicing

C:\Windows\System32

C:\Windows\Installer

Do not:

Run a batch file that deletes WinSxS subfolders.
Change WinSxS permissions.
Use Unlocker-style tools to remove component files.
Delete random folders named after older versions.
Move the component store to another drive.
Compress individual files inside WinSxS manually.
Use a third-party cleaner that promises to remove “duplicate Windows files.”
Delete servicing manifests or package catalogues.

Hard-linked files that appear duplicated may represent one required physical file. Deleting the wrong link or servicing record can make Windows unable to update, repair itself or start.

Should You Compress the Windows Drive?

Windows supports NTFS compression and Compact OS techniques, but compressing the complete Windows drive purely because WinSxS looks large should not be the first response.

Compression can:

Increase processor work
Complicate performance diagnosis
Provide limited benefit on already compressed files
Mask an undersized system drive
Leave the computer with insufficient working space for future updates

Start with:

Storage Sense
Cleanup recommendations
Disk Cleanup
WinSxS analysis
Standard component cleanup
Application and user-data review

When the system drive remains continually full, increasing its capacity may be the more reliable long-term solution.

How Much Free Space Should You Keep?

Windows requires working space for:

Monthly updates
Feature updates
Temporary files
Page-file growth
Application installations
Browser and Microsoft 365 caches
Restore points
Recovery operations

Microsoft states that Windows checks whether sufficient space exists before installing updates and recommends Storage Sense and Cleanup recommendations when more capacity is required.

Rather than operating continuously with only a few hundred megabytes free, aim to maintain meaningful headroom.

The exact amount depends on:

Drive capacity
Installed applications
Windows edition
Page-file requirements
Feature-update size
User workload

A 128GB system drive running several business applications may require more frequent management than a 1TB SSD.

A Safe Post-Update Cleanup Checklist

After a significant Windows update:

Restart Windows.
Confirm the update completed successfully.
Test business applications.
Test printers, Wi-Fi, Bluetooth and displays.
Confirm Windows activation.
Check BitLocker and Windows Security.
Back up important files.
Check available storage.
Open Storage and review Cleanup recommendations.
Remove temporary files you understand.
Retain Windows.old until the upgrade is proven stable.
Run Disk Cleanup as administrator.
Run AnalyzeComponentStore.
Check whether cleanup is recommended.
Run normal StartComponentCleanup where appropriate.
Restart.
Analyse the component store again.
Use /ResetBase only after considering its rollback consequences.
Never delete WinSxS manually.
Investigate the wider drive when free space remains low.

How Hamilton Group Can Help

WinSxS cleanup is normally straightforward when Windows servicing is healthy.

When the folder continues growing, cleanup fails or the computer remains critically low on storage, the issue may require a wider investigation.

Hamilton Group’s experienced IT team can help with:

Storage Analysis

We can identify how much space is genuinely being consumed by:

WinSxS
Windows.old
Update downloads
Temporary files
User profiles
Outlook data
Application caches
Restore points
Memory dumps
Page files

Safe Windows Cleanup

Hamilton Group can safely run and interpret:

Storage Sense
Cleanup recommendations
Disk Cleanup
DISM component-store analysis
StartComponentCleanup
Windows image-health checks

Windows Servicing Repair

Where cleanup or updates fail, we can investigate:

Component-store corruption
Failed cumulative updates
Pending servicing operations
DISM and CBS logs
Windows Update components
Recovery Environment problems

Storage Upgrades

When the existing drive is simply too small, we can:

Check SSD compatibility
Supply a suitable replacement
Clone a healthy installation
Perform a clean Windows installation
Restore applications and data
Test BitLocker, activation and recovery

Business-Wide Maintenance

For managed environments, Hamilton Group can monitor:

Low-disk-space devices
Failed Windows updates
Unsupported Windows versions
Oversized user profiles
Storage-health warnings
Devices unable to complete component cleanup

Hamilton Group aims to make first contact on IT support requests within 15 minutes, helping businesses restore working space before low storage interrupts updates and everyday work.

Clean the Component Store—Do Not Attack the Folder

WinSxS is not a collection of disposable duplicates. It is a core part of Windows servicing and recovery.

The safe process is:

Analyse

Review

Clean with Windows tools

Restart

Analyse again

Start with Storage settings and Disk Cleanup. Use:

Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore

to establish whether meaningful storage is reclaimable, followed where appropriate by:

Dism.exe /Online /Cleanup-Image /StartComponentCleanup

Reserve /ResetBase for situations where Windows is stable and you knowingly accept that existing update packages will no longer be removable.

Call 0330 043 0069, book a meeting with one of our experts or visit hgmssp.com for experienced help with Windows storage, updates and component-store cleanup.

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