Microsoft has acknowledged that the April 2025 Windows security update creates a new, empty "inetpub" folder on user systems, advising against its deletion. This folder is associated with Internet Information Services (IIS) but appears even on systems without IIS installed. The folder is created using the SYSTEM account, and while deleting it does not disrupt Windows functionality, Microsoft emphasizes it should remain untouched. The existence of the C:inetpub directory prior to the update may cause installation failures of the cumulative updates. Microsoft has updated its advisory regarding a security vulnerability (CVE-2025-21204) related to improper link resolution within the Windows Update Stack, warning that exploitation could allow local attackers to escalate permissions. Users can recreate the C:inetpub folder by installing IIS through the Windows Features control panel, and uninstalling IIS will remove the software but leave the folder intact.