Why is Windows 11’s April update creating a mysterious ‘inetpub’ folder?

Microsoft’s April update—KB5055523 for Windows 11 24H2—is currently rolling out via Windows Update. According to Microsoft, the cumulative update fixes several security vulnerabilities in Windows 11 while also introducing some minor improvements.

But on top of all that, users have spotted a new and rather curious phenomenon: after installing KB5055523 and restarting Windows 11, a new folder called inetpub suddenly appears in the C: drive, which was created by the update. I was personally able to observe this on my own computer after installing update KB5055523.

Foundry

The inetpub folder is normally created and used by Windows Internet Information Services (IIS), an optional web server by Microsoft that’s integrated into Windows and enables the hosting of websites, apps, and FTP servers directly on a Windows PC. The required web data is subsequently stored in the inetpub folder.

Emphasis on “optional,” though, as IIS isn’t normally installed on Windows 11 Home or Windows 11 Pro and is usually only installed on demand by turning it on via the Windows Features panel:

Joel Lee / Foundry

Did update KB5055523 simply install and activate IIS without my knowledge? The good news is, no, IIS is still disabled. It remains unclear why the folder was created, the, but it’s presumably a minor bug on Microsoft’s part that simply crept into KB5055523. This is supported by the fact that the folder is completely empty and therefore useless.

There’s currently no information from Microsoft about the inetpub problem. You can delete the inetpub folder without worry, or wait until Microsoft delivers a hotfix that removes the folder again.

Apart from this issue, the April update KB5055523 is far from bug-free. Microsoft refers to several known issues on the official support page for the update, including some that affect Roblox as well as Citrix apps and Windows Hello.

Gamers using Arm devices are unable to download and play Roblox on Windows from the Microsoft Store, and devices with certain Citrix components installed may not be able to install the January 2025 Windows security update. Microsoft is also investigating issues that are preventing users from signing in with Windows Hello facial recognition or PIN, requiring them to re-register first.