Question What on the Windows system actually needs to be cleaned?

[lokamoka820]

Since the start of the year, I've been having problems with Windows updates that sometimes it goes back to the previous release and then require a fix update to reinstall the 25H2 update. Some reliable members have suggested that using third-party system cleaners (including registry cleaners) could be the cause of this problem; perhaps using third-party uninstallers carelessly could lead to this situation too.

This time, as part of my regular maintenance round, I updated Windows entirely (including the fix update and all other updates found), paused the update for five weeks (the maximum permitted period), and simply used the built-in Windows storage temporary files cleaner. Despite this, I still feel like something is missing because I'm a system utility person.

Now, I'm wondering if I really need to clear out everything that is typically found on third-party cleaners, such as the cache from the Microsoft Store, DNS, browser, etc., or if this is all unnecessary and from the past.

Many thanks

 

[Bot]

Since the start of the year, I've been having problems with Windows updates that sometimes it goes back to the previous release and then require a fix update to reinstall the 25H2 update. Some reliable members have suggested that using third-party system cleaners (including registry cleaners) could be the cause of this problem; perhaps using third-party uninstallers carelessly could lead to this situation too.

This time, as part of my regular maintenance round, I updated Windows entirely (including the fix update and all other updates found), paused the update for five weeks (the maximum permitted period), and simply used the built-in Windows storage temporary files cleaner. Despite this, I still feel like something is missing because I'm a system utility person.

Now, I'm wondering if I really need to clear out everything that is typically found on third-party cleaners, such as the cache from the Microsoft Store, DNS, browser, etc., or if this is all unnecessary and from the past.

Many thanks

It is very possible that less is better here.

Why third-party cleaners can cause update problems

Windows feature updates and cumulative updates rely on a lot of things staying intact:

• Component store files
• Windows Update cache and servicing data
• Registry entries used by installers and rollback
• Scheduled tasks and services
• App package data for built-in components

Some third-party cleaners, especially registry cleaners and aggressive “system optimizers,” may remove entries or files that look unused but are still needed by Windows Update. That does not always break the system immediately, but it can contribute to failed installs, rollback to the previous build, or repeated repair/fix updates.

The same general risk applies to some uninstallers if they are used in aggressive cleanup mode. Removing leftovers manually is not always harmful, but force-removing shared components, services, installer data, or registry entries can create hard-to-trace update issues later.

Do you need to clear Store cache, DNS cache, browser cache, and similar items?

In general, no. Most of that is optional maintenance, not something Windows needs for stability.

• Browser cache: usually harmless to keep; clearing it mainly helps with website loading issues, privacy, or reclaiming a small amount of space.
• DNS cache: normally resets on its own over time; flushing it is mainly useful for name resolution problems after DNS changes or network troubleshooting.
• Microsoft Store cache: usually only worth clearing if the Store is misbehaving, downloads are stuck, or app installs fail.
• Temporary files: reasonable to clean occasionally with Windows’ built-in tools, especially if disk space is low.

So if your system is working normally, regularly clearing all of those caches is usually unnecessary.

What is still worth doing as routine maintenance

A conservative approach is usually the safest one:

• Keep Windows fully updated
• Use Windows Security or another reputable antivirus
• Use Storage Sense or Disk Cleanup / Temporary files in Windows Settings
• Keep enough free disk space available for updates
• Restart occasionally instead of only using sleep/hibernate for very long periods
• Update drivers only from Windows Update or the hardware vendor when actually needed

That approach is much less likely to interfere with servicing.

About registry cleaners specifically

Registry cleaners are one of the least useful categories of “maintenance” tools on modern Windows.

In general:

• They rarely provide a measurable performance benefit
• They can remove entries that are still needed
• Any “errors found” count is often not meaningful
• The risk is usually higher than the benefit

That is why many experienced users recommend avoiding them entirely, especially on a system already showing update instability.

What to do if Windows Update keeps rolling back

If the problem continues even without third-party cleaners, the cause may be elsewhere. Safer next steps would be:

• Run:
  • sfc /scannow
  • DISM /Online /Cleanup-Image /RestoreHealth
• Check that you have adequate free space on the system drive
• Temporarily avoid non-essential tweaking tools, cleaners, and aggressive uninstallers
• Review setup error information in Windows Update history and Event Viewer
• If needed, perform an in-place repair install using official Microsoft installation media

An in-place repair install is often much more effective than repeated cleaning attempts when update servicing has become unreliable.

Bottom line

You do not need to routinely clear every cache and leftover category that third-party cleaners advertise. For most systems, that is unnecessary, and aggressive cleaning can make Windows updating less reliable rather than more reliable.

The safest maintenance routine is usually the built-in Windows tools plus a minimal-touch approach.

 

[Halp2001]

Great topic you raised, @lokamoka820. We still carry the habit from the Windows XP era, when cleaning the system was almost a survival requirement.

Today things are different: Windows manages itself much better.

• Temporary files: just use what the system already provides (Storage Sense or Disk Cleanup). These tools know exactly what’s junk and what’s critical for the next update.
• Specific caches: browser or Store, only if you notice issues. Clearing them “just because” only makes the next load slower.
• External optimizers: registry cleaners are often the number one enemy of updates. They delete entries Windows expects to find, and that’s when the failed installation loops begin.

In short, less is more. The best maintenance today isn’t “deleting things,” but simply letting Windows Update do its job and avoiding aggressive uninstallations. Sometimes the best technician is the one who doesn’t touch what already works.

 

[Miraculix]

I fundamentally distrust system optimizers and system cleaners and therefore never use them.

 

[Zero Knowledge]

It's like cleaning the stops any germs & from getting sick (Windows) until you realize everything else is vulnerable & sending back data (Apps) so all we have is

 

[Sorrento]

If you Windows install is anything but simple & mine are not, regular imaging & the saving of a start & final of each month at least from the preceding weeks will usually get you out of a problem by in my case simply going back days weeks etc, for me its fundamental to keeping a system as I like it, especially as many portable programs are on a separate drive from C:\ - Personally I don't find running the junk cleaner in Hi-Bit uninstaller does any harm, I usually use the built in MS Cleaner though & I don't keep history cookies etc.

Giving C:\ lots of room to play with I feel helpful, the last thing we need is an OS drive with no room - I had an issue last year with a neighbors PC & I ended up manually installing a KB, that sorted his update issue, but I did have an image from earlier though as it was a while back many things had changed so I encouraged him to image more often. Registry cleaning can & will cause issues in the future, I do however after uninstalling a program & I try not to install & uninstall these days as I know what I like, I do use registry search & remove unwanted entries manually, & folders of programs no longer on your system can be removed.

If I wish to test a program I always do a full C:\ image first, (this IMO is critical especially with AV programs Office, etc) if I don't like it I go back to a nice clean OS - My 25 pence worth - If the system is messed up badly a clean install is really the answer, I've only had to do that once in 5 years though with I feel some good housekeeping

 

[TairikuOkami]

It's like cleaning the stops any germs & from getting sick (Windows)

Exactly, it is not about fixing the problem, but preventing it. People with issues always ask, why me, and are usually advised to reinstall, it is like killing a fly with a nuke.
I will never forget when 10 failed to update, the issue was caused by an empty reg entry, people using reg cleaners were OK, MS released a reg cleaner update as the fix.

P.S. I have just performed an upgrade and I always do a cleanup afterwards to keep system smooth and partition small, thus a system backup takes roughly only 30 secs.
I did not start to use cleanup because I was bored, but to prevent problems and it obviously worked, I have not had BSOD for decades and all minor problems are gone.

 

[Marko :)]

I agree with what @Bot said.

 

[Bot]

I agree with what @Bot said.

A small correction on the “registry cleaners prevented an update issue” point

That can happen in a very specific case, but it should not be taken as a general argument in favor of routine registry cleaning.

• Sometimes a Windows update or upgrade fails because of one bad or orphaned registry value.
• In those cases, removing that exact problem entry can help.
• But that is very different from running a general-purpose registry cleaner across the whole system as maintenance.

The main problem is that registry cleaners do not reliably distinguish between safe to remove and still needed later. A tool may appear to “fix” one edge case while increasing the risk of servicing, rollback, installer, or application problems elsewhere.

What is safer in practice

For long-term stability, the lower-risk approach is usually:

• Use built-in Windows cleanup tools for temporary files
• Keep good free space on C:
• Make regular system images if the setup is important to you
• Avoid aggressive optimizer/cleaner routines
• Only remove a registry entry manually when there is a documented reason to remove that exact entry

About imaging and backups

The point about regular imaging is strong. A current system image is often far more useful than any cleaner because it gives you a known-good rollback path without guessing what broke.

That said, an image backup is a recovery strategy, not proof that a cleanup method is safe. Both ideas should be kept separate.

Bottom line

Targeted fixes for a confirmed update problem are one thing. Routine cleaner use as preventive maintenance is another. In general, the second offers limited benefit and more risk on modern Windows.

So the safest conclusion is still: use built-in cleanup for normal maintenance, keep backups/images, and avoid broad registry cleaning unless there is a specific, verified reason.

 

[pxxb1]

Since the start of the year, I've been having problems with Windows updates that sometimes it goes back to the previous release and then require a fix update to reinstall the 25H2 update. Some reliable members have suggested that using third-party system cleaners (including registry cleaners) could be the cause of this problem; perhaps using third-party uninstallers carelessly could lead to this situation too.

This time, as part of my regular maintenance round, I updated Windows entirely (including the fix update and all other updates found), paused the update for five weeks (the maximum permitted period), and simply used the built-in Windows storage temporary files cleaner. Despite this, I still feel like something is missing because I'm a system utility person.

Now, I'm wondering if I really need to clear out everything that is typically found on third-party cleaners, such as the cache from the Microsoft Store, DNS, browser, etc., or if this is all unnecessary and from the past.

Many thanks

What these reliable members mean is that those cleaners can cause errors on the OS and therefore the updates can not be installed. Windows is not reading things right. That can usually be fixed by running either sfc /scannow or Dism, or both. After running that the updates can be installed. As said, usually. I have experienced that even though the mentioned tools repaired or did not find any issue the updates could not be installed on a specific OS backup image. After changing to another OS image with my backup program it did. Windows is a mystery sometimes.

But these problems can not be caused by standard cleaners, only by reg.cleaners and uninstallers. Uninstallers also cleans the registry when uninstalling. Standard cleaners that clean items like those in the Windows Disc clean tool are always safe to use. If needed to. Because cleaning is not needed under usual circumstances for a home user. This cleaning frenzy is an obsession still hanging around since Windows XP. But for the browser it can be good to do it, otherwise it can grow enormously large.

So, you have to change habits. Clean with Windows built in tool, and optimize/defrag and do your backup. Thats it.

If you want to stops updates for as long as you wish, there are tools for it.

 

[Marko :)]

Despite this, I still feel like something is missing because I'm a system utility person.

Now, I'm wondering if I really need to clear out everything that is typically found on third-party cleaners, such as the cache from the Microsoft Store, DNS, browser, etc., or if this is all unnecessary and from the past.

It seems like you still have a habit from Windows 7 era where you needed to run few "system optimizer" tools. Since Windows 10, most of these are cleaned on the go by Windows itself. By deleting unnecessary registry keys you're not really benefiting from anything. These are just old settings left by software after uninstallation.

Regarding Microsoft Store, if you have issues with it, yes go ahead and clean the cache (I'd even recommend you to reset it). Unless you have problems with it, the you don't need to do anything. Same goes for DNS; there's a thing called TTL, a time specifying how long will DNS response be cached before reaching DNS servers again. It is good idea to set browser to clean site data occasionally or on exit for privacy reasons though.

 

[Sorrento]

Interestingly after a recent install I was looking in disc management shortly after & for unknown reasons I saw C:\ was compressed, now there is heaps of room on C with 200 GIG free, so I'll never know how really know why it came on and as the PC is fast & without any need for compression as no files that need it so I removed it & indeed its livelier as expected never happened before so...???

 

[lokamoka820]

I discovered that my Windows version had reverted once more after starting this thread, and the previous start menu was back.

 

[Marko :)]

I discovered that my Windows version had reverted once more after starting this thread, and the previous start menu was back.

Settings -> System -> Recovery -> Fix problems using Windows Update -> Reinstall now button.

This will keep everything as it is, but it will reinstall Windows using fresh image from Windows Update. If you can't solve an issue, this will most likely fix it. And my recommendation, try not to use system cleaners, optimizers and telemetry destroyers anymore. I bet that they are the ones making issues; they did for me in 2016 after which I got rid of them all.

Although, I would recommend resetting Windows entirely, just to be sure garbage is gone completely.

 

[Parkinsond]

Erasing temporary files will only lead to more rapid consumption of SSD after being recreated.

 

[Marko :)]

Erasing temporary files will only lead to more rapid consumption of SSD after being recreated.
View attachment 296835

Correct! Hence why I made Firefox delete everything except cache and cookies from specific sites on exiting. Clearing cache constantly would massively impact SSD health on a long term.

 

[MWTSenior]

I usually clean following:

• %TEMP% and %TMP%
• Temporary files or cache in browsers