Skip to main content

Frequently Asked Questions

General​

Is O&O AppBuster really free?​

Yes. O&O AppBuster is freeware: free of charge, without a time limit, without registration, and usable on as many PCs as you like. See Freeware.

Is there a Pro, Premium or Enterprise version of O&O AppBuster?​

No. There is exactly one version, and it is the one described in this documentation. If a website offers you a paid "Pro version of O&O AppBuster", it is not from us.

When you close O&O AppBuster, it may show links to other O&O products and an optional newsletter form. See More O&O products.

Do I have to install it?​

No. O&O AppBuster is a single executable. Download it, run it, delete it again when you are done. Its only footprint is a configuration file in your user profile.

Which Windows versions are supported?​

Windows 10 and Windows 11, on x64 and ARM64. Earlier Windows versions are not supported — they do not have the modern app platform O&O AppBuster is built around. See System requirements.

Does it install any additional software?​

No. O&O AppBuster comes on its own. If you obtained a version whose installer offers toolbars or "optimisers", it was repackaged by a third party — please let us know where you found it.

Does it run in the background?​

No. O&O AppBuster works while it is open and leaves nothing behind when you close it. There is no service, no scheduled task and no autostart entry.

Starting the program​

Why does it require administrator rights?​

Because everything it does needs them: uninstalling apps, deleting registry entries and files, and creating a system restore point. Asking once at startup means you get a single UAC prompt per session instead of one for every action.

Can I use it without administrator rights?​

No. Without them the program cannot start.

The scan takes a long time. Is something wrong?​

Probably not. The scan enumerates the Windows package system and several registry locations; on a PC with many desktop programs this takes longer. Sizes on disk are calculated in the background afterwards, which is why the Storage column keeps filling in after the list has appeared.

Which languages does the interface support?​

English, German, French, Spanish, Italian, Russian, Japanese and Chinese. Change it under File → Settings → General; the program restarts to apply it.

The app list​

Why do I see far more apps than in the Windows Apps & features page?​

Because Windows only shows you part of the picture. O&O AppBuster additionally lists system apps, framework apps, hidden apps, staged packages and the leftovers of earlier uninstallations, and it reads registry locations the Windows dialog ignores. See App categories.

The list is shorter than I expected. Where did the rest go?​

One of the View menu options is hiding them — most likely Show Microsoft apps or Show system and framework apps. Whenever that is the case, a notice above the list says how many apps are hidden and offers Show all.

Why can I not uninstall some apps?​

They are system apps or framework apps. Windows and other programs depend on them, so they are shown for information only, with the status Unremovable. See System and framework apps.

What do "keep", "optional" and "remove" mean?​

They are O&O AppBuster's recommendations. remove means nothing depends on the app; optional means removing it is safe but it is a matter of taste; keep means leave it alone. Anything O&O AppBuster does not explicitly classify defaults to keep. See Recommendations.

An app I never use says "keep". Why?​

Because O&O AppBuster does not recognise it and will not guess. A wrong keep costs you some disk space; a wrong remove could break something. Decide for yourself using the app's properties.

How do I find the apps that use the most space?​

Sort by Storage in descending order. Combined with the Recommended removal chip, this is the quickest route to a noticeable amount of free space.

Removing apps​

Can I undo a removal?​

Not from within O&O AppBuster directly. Your options are:

  • Windows apps — install them again from O&O AppBuster, or get them from the Microsoft Store.
  • Desktop apps — reinstall from their own setup file.
  • Everything — restore a system restore point created beforehand.

What is the difference between the three removal scopes?​

Current user removes the app from your account only. All users removes it from every account on the PC. Entire PC — including files removes it everywhere and deletes its leftover files from disk. The last one is the most thorough and frees the most space. See Removing apps.

Why can I not choose a scope for some apps?​

Because they are desktop apps. Desktop apps are removed by their own uninstaller and have no concept of per-user removal. The removal dialog tells you when your selection contains desktop apps.

Why does another window open during a removal?​

That is the desktop app's own uninstaller. O&O AppBuster starts it and waits for it to finish, because the uninstaller knows about services, drivers and file associations a generic remover would miss. You may have to confirm its dialogs.

An app was skipped because a file is in use. What now?​

The result dialog offers three ways forward: Close these programs and remove, Remove on next restart, or Skip this app. If you choose the second one, restart your PC to complete the removal.

Can I get a record of what was removed?​

Yes. The result dialog has a Save log… button which writes a report with the scope, the apps removed, and the apps skipped along with the reasons.

I removed an app and it came back after a Windows update.​

That happens — feature updates reinstall apps that Windows considers part of the experience. Start O&O AppBuster after a big update and check the Newly discovered Smart View; anything that reappeared will be there.

Leftovers, orphaned and defect apps​

What is an "orphaned" app?​

A leftover: the program was uninstalled but its data folder, registry entries or installer registration are still there. They take up space and can block a later reinstallation. See Orphaned apps.

What is a "defect" app?​

An MSI-installed program whose cached installer package has gone missing. Windows can no longer uninstall, repair or update it, although the program itself often still works. See Defect apps.

Is it safe to remove orphaned entries?​

Usually, but this is the most invasive thing O&O AppBuster does — there is no uninstaller involved that could know better. Create a system restore point first, check the Confidence field in each entry's properties, and work through them one at a time rather than selecting all of them at once.

Be especially careful with entries that look like an add-in, a plugin, a service or a helper for a program you still use — those may be components of a program that is still installed.

The Orphaned or Defect chip is not there.​

Then nothing was found in that category. That is the good case.

Why does a program refuse to reinstall even though I uninstalled it?​

Very often because a ghost Windows Installer registration is left behind: Windows still believes the software is installed. Look at the Orphaned Smart View — removing that registration usually solves it.

Updates​

Why is the update feature not available?​

It needs the Windows Package Manager (winget), which comes with the App Installer package from the Microsoft Store. If it is not present, the setting is disabled and says so. Install App Installer from the Store to enable it.

Why did an individual update fail?​

Updates are carried out by the Windows Package Manager, not by O&O AppBuster. An update can fail because the app is running, because the publisher's download is temporarily unavailable, or because the app is not in the winget catalogue under the name Windows recorded for it.

Can O&O AppBuster install updates automatically?​

No. It updates apps when you ask it to and does not run in the background. If you want that, winget upgrade --all in a scheduled task is the Windows-native way.

Does it also update Windows apps from the Store?​

No. Those are updated by the Microsoft Store itself.

Data and privacy​

Where does O&O AppBuster store its settings?​

In one file in your user profile:

%LocalAppData%\OO Software\OO AppBuster\OOAppBuster.cfg

Delete it to reset the program to its defaults.

Where is the log file?​

Next to the configuration file, as OOAppBuster.log — but only if you switched logging on under File → Settings → Advanced. It is off by default.

Does O&O AppBuster send data anywhere?​

The program checks for new versions online when you ask it to. The product window opens product pages in your browser, and the newsletter form sends the email address you enter only after you select Subscribe. O&O AppBuster does not transmit an inventory of your apps.

Does O&O AppBuster change my privacy settings?​

No. O&O AppBuster only manages apps. O&O ShutUp10 is available separately for Windows privacy settings; see More O&O products.

Support​

How do I stop the product window from appearing when I close AppBuster?​

Select Do not show this message again in the product window. This disables its automatic display, but you can still open it from Help → Explore more O&O products....

Where do I get help?​

  • This documentation — reachable from the program via Help → Online help or the F1 key.
  • The O&O support pages.

If you contact support about a problem, switch logging on first (File → Settings → Advanced), reproduce the problem, and attach OOAppBuster.log.

How do I know which version I have?​

Help → About. The dialog also shows system information about your Windows installation, and offers Check online for new version.