Forum Discussion

zlqqpybucguf's avatar
zlqqpybucguf
Copper Contributor
Nov 08, 2026

Windows 10 ISO mounting bugs

Short description: current windows 10 ltsc freezes when trying to mount an iso file, especially a windows installation image.

 

Setup: Windows 10 IoT Enterprise LTSC 2021 x64 en-US. Clean installed from '

en-us_windows_10_iot_enterprise_ltsc_2021_x64_dvd_257ad90f.iso'.

 All updates have been fully done, including latest cumulative updates(KB5126657), servicing stack updates, .NET framework updates(4.8.1), and any other hardware-dependent driver updates.

 

When I try to open and mount a windows installation image (iso), the explorer freezes, and is unresponsive. ISO files that are not Windows installation images open fine, and even when explorer is frozen, other parts of Windows work totally fine(like browsers).

 

This behavior hasn't been seen before the 2026-10 cumulative updates. Maybe the KB5126657 has something to do with it?

 

PC hardware: i9-10900KF, DDR4 32GB RAM, 1TB NVMe SSD, Z490 MB. I've been using this PC with the exact same OS for years, and this is the first time experiencing such issue.

 

Tried troubleshooting with claude code and codex, but failed (mainly due to session halting by cybersecurity flags)

explorer
Freeze
ISO
Windows10

1 Reply

  • Jamony's avatar
    Jamony
    MCT
    Nov 11, 2026

    You have narrowed this to Windows installation ISOs on IoT Enterprise LTSC 2021: Explorer hangs, but other applications and other ISO images remain usable. The timing after KB5126657 is useful evidence, but Microsoft’s current release notes do not list this ISO-mounting problem. Test the same ISO through PowerShell using Mount-DiskImage, setting -ImagePath to its full quoted path and adding -PassThru. Microsoft documents this as a supported way to mount an ISO read-only. Record whether the command completes, returns an error, or hangs; then use Get-DiskImage to check its mounted state. Dismount it with Dismount-DiskImage before repeating. A successful command with an Explorer-only hang points the investigation toward the shell; both hanging requires investigating beyond Explorer. Compare one affected installation ISO and one working ISO, recording exact builds and timestamps. Give Microsoft Support these results rather than assuming the update is defective or disabling security software to mount it.