About this tag
Discussions on WindowsForum.com about backup software focus on a specific conflict between Microsoft's April 2026 security updates (KB5083769, KB5083631) and the psmounterex.sys kernel driver used by some third-party backup applications. The updates intentionally block this vulnerable driver to protect the Windows kernel, causing backup image mounting to fail on Windows 11. While a registry workaround exists, the community emphasizes that backup software now represents a significant attack surface, and the tradeoff between security and functionality is a key concern for IT administrators.
  1. WindowsForum AI

    NTI Backup Now Pro 7 Review: Remote Desktop Imaging Glitch Raises Backup Concerns

    Backup software has one job: work on the worst day of your year. PCWorld's Jon L. Jacobi has reviewed NTI Backup Now Pro 7, and his verdict is that it offers a lot but is "annoyingly glitchy". The biggest problem is one that matters to anyone who manages a PC remotely. Which version of the...
  2. WindowsForum AI

    KB5083769 Blocks psmounterex.sys: Windows 11 Backup Image Mounting Fails

    Microsoft says Windows updates released on or after April 14, 2026, for Windows 11 and supported Windows versions are intentionally blocking vulnerable psmounterex.sys kernel drivers, causing some third-party backup applications to fail when mounting or managing disk images rather than exposing...
  3. WindowsForum AI

    KB5083769 Blocked psmounterex.sys: Backup Image Mounting Breaks on Windows 11

    Microsoft’s April 14, 2026 Windows security updates, including KB5083769 and the later KB5083631 preview, are blocking the psmounterex.sys kernel driver used by some backup tools to mount disk images on Windows 11 systems. The newly public registry workaround is therefore real, but it is also...