Microsoft reports how CCleaner installer with Nullsoft plugin offers unwanted applications. The company says CCleaner instalers use a Nullsoft plugin to offer different products during installation and comes bundled with following applications: To protect Windows users, Microsoft Defender Antivirus detects CCleaner installers that exhibit this behavior as potentially unwanted applications (PUA)”.įor instance, it cites CCleaner bundling with Avast antivirus may disable Microsoft Defender Antivirus if the user opts into installation accidentally. Microsoft said “bundling of software, especially products from other providers, can result in unexpected software activity that can negatively impact the user experiences.

You may not have appropriate permission to access them”. ” Windows cannot access the specified device, path, or file. If you download Speccy, Recuva, and Defraggler, their setup files will be locked but not removed, and you’ll receive an error: On the other side, Windows Defender acts more aggressively on other products of Avast. The issue can also be seen reported on Reddit.Īs of now, we can confirm CCleaner can be installed without any issues on Windows 10, but you’ll still see it being marked as PUA in Protection History. You should note that the newly available PUA Protection feature in Windenabled by default is causing this.

Microsoft has come up with an explanation of why it has flagged popular Cleaning tool as “PUA: Win32/CCleaner”.ĬCleaner users rushed to report on Piriform forums that Windows Defender is reporting CCleaner as Potentially Unwanted App. And Windows 10 is locking other Piriform product installers such as Recuva, Defraggler, and Speccy from running. Apparently, Windows Defender in Windows 10 is classifying CCleaner Installer as Potentially Unwanted Application (PUA).

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